diff --git a/arvo/clay.hoon b/arvo/clay.hoon
index 12d171386..9ba939333 100644
--- a/arvo/clay.hoon
+++ b/arvo/clay.hoon
@@ -78,7 +78,6 @@
               [%dune p=(set beam) q=(unit cage)]        ::  unit literal
               [%mute p=silk q=(list (pair wing silk))]  ::  mutant
               [%pact p=silk q=silk]                     ::  patch
-              [%plan p=beam q=spur r=hood]              ::  structured assembly
               [%reef ~]                                 ::  kernel reef
               [%ride p=twig q=silk]                     ::  silk thru twig
               [%vale p=mark q=ship r=*]                 ::  validate [our his]
@@ -97,7 +96,7 @@
           $:  lim=@da                                   ::  complete to
               qyx=cult                                  ::  subscribers
               ref=(unit rind)                           ::  outgoing requests
-              wok=work                                  ::  outstanding diffs
+              wok=(unit work)                           ::  outstanding diffs
               dom=dome                                  ::  revision state
           ==                                            ::
 ++  riff  ,[p=desk q=(unit rave)]                       ::  request/desist
@@ -290,58 +289,61 @@
           |  :_  yel
              [hen %note '=' %leaf :(weld (trip p.lem) " " (spud pre))]
           &  |-  ^+  yel
-             ?~  q.q.lem  yel
-             :_  $(q.q.lem t.q.q.lem)
+             ?~  q.p.lem  yel
+             :_  $(q.p.lem t.q.p.lem)
              :-  hen
              :+  %note
-               ?-(-.q.i.q.q.lem %del '-', %ins '+', %mut ':')
-             [%leaf (spud (weld pre p.i.q.q.lem))]
+               ?-(-.q.i.q.p.lem %del '-', %ins '+', %mut ':', %dif ';')
+             [%leaf (spud (weld pre p.i.q.p.lem))]
         ==
       ==
     ::
     ++  edit                                            ::  apply changes
       |=  [wen=@da lem=nori]
       ^+  +>
-      ?.  -.lem
+      ?:  ?=(%| -.lem)
         =+  axe=(~(edit ze lim dom ran) wen lem)
         =+  `[l=@da d=dome r=rang]`+<.axe
-        +>.$(dom d, ran r)
-      ?^  wok
+        +>.$(dom d, ran r)                              ::  XX  checkout-ankh
+      ?.  =(~ wok)
         ~&  %already-applying-changes  !!
       =+  ^-  lon=(list path)
-          (murn q.p.lem |=([a=path b=miso] ?.(?=(%mut -.b) ~ `a)))
+          (murn q.p.lem |=([a=path b=miso] ?.(?=(%mut -.b) ~ (some a))))
       =+  ^-  sot=(list ,[p=path q=misu])
-          (murn q.p.lem |=([a=path b=miso] ?:(?=(%mut -.b) ~ `[a `misu`b])))
-      =.  wok `[sot lon]
+          %+  murn  q.p.lem
+          |=([a=path b=miso] ?:(?=(%mut -.b) ~ (some [a `misu`b])))
+      =.  wok  `[sot lon]
       ?~  lon
-        apply-edit
+        (apply-edit wen)
       =+  ^-  los=(list ,[duct path note])
-          (murn q.p.lem |=([a=path b=miso] ?.(?=(%mut -.b) ~ `(silkify a b))))
+          %+  murn  q.p.lem
+          |=([a=path b=miso] ?.(?=(%mut -.b) ~ (some (silkify wen a b))))
       %_(+>.$ tag (welp los tag))
     ::
     ++  silkify
-      |=  [a=path %mut b=cage c=cage]
+      |=  [wen=@da a=path %mut b=cage c=cage]
       ^-  [duct path note]
       :+  hen
-        [%diffing (scot %p who) syd a]
+        [%diffing (scot %p who) syd (scot %da wen) a]
       [%f %exec who ~ %diff [%done ~ b] [%done ~ c]]
     ::
     ++  apply-edit
-      ^-  .
+      |=  wen=@da
+      ^+  +>
       ?~  wok  ~&  %no-changes  !!
       ?^  lon.u.wok  ~&  %not-done-diffing  !!
-      =+  axe=(~(edit ze lim dom ran) wen %& *cart wok.wok)
+      =+  axe=(~(edit ze lim dom ran) wen %& *cart sot.u.wok)
       =+  `[l=@da d=dome r=rang]`+<.axe
-      +>(dom d, ran r, wok ~)
+      +>.$(dom d, ran r, wok ~)                         ::  XX  checkout-ankh
     ::
     ++  take-diff
-      |=  [pax=path res=(each bead (list tank))]
+      |=  [wen=@da pax=path res=(each bead (list tank))]
       ^+  +>
       ?~  wok
         ~&  %clay-unexpected-made  !!
       ?.  (lien lon.u.wok |=(path =(+< pax)))
         ~&  %clay-strange-made  !!
-      ?.  -.res
+      ?:  ?=(%| -.res)
         %_    +>.$
             wok  ~
             tag
@@ -349,17 +351,17 @@
           ^-  (list ,[duct path note])
           %+  murn  lon.u.wok
           |=  a=path
-          ?:  =(pax a)
-          `[hen [%diffing (scot %p who) syd a] %f %exec who ~]
+          ?:  =(pax a)  ~
+          `[hen [%diffing (scot %p who) syd (scot %da wen) a] %f %exec who ~]
         ::
             yel
           [[hen %note '!' %rose [" " "" ""] leaf/"clay diff failed" p.res] yel]
         ==
-      =:  lon.wok  (skip lon.u.wok |=(path =(+< pax)))
-          sot.wok  [[pax %dif q.p.res] sot.u.wok]
+      =:  lon.u.wok  (skip lon.u.wok |=(path =(+< pax)))
+          sot.u.wok  [[pax %dif q.p.res] sot.u.wok]
       ==
       ?~  lon.wok
-        apply-edit
+        (apply-edit wen)
       +>.$
     ::
     ++  edis                                            ::  apply subscription
@@ -797,12 +799,13 @@
       [[[hen %slip %d %flog +.q.hin] ~] ..^$]
     ::
         %made
-      ?>  ?=([%diffing @ @ *] tea)
+      ?>  ?=([%diffing @ @ @ *] tea)
       =+  who=(slav %p i.t.tea)
       =+  syd=(slav %tas i.t.t.tea)
+      =+  wen=(slav %da i.t.t.t.tea)
       =^  mos  ruf
         =+  ^=  zat
-          (take-diff:(di:wake:une syd) t.t.t.tea p.q.hin)
+          (take-diff:(di:wake:une syd) t.t.t.t.tea p.q.hin)
         =+  zot=abet.zat
         [-.zot abet:(pish:une syd +.zot ran.zat)]
       [mos ..^$]
diff --git a/arvo/zuse.hoon b/arvo/zuse.hoon
index d4bee3555..9de08ebb0 100644
--- a/arvo/zuse.hoon
+++ b/arvo/zuse.hoon
@@ -2,6 +2,7 @@
 ::  zuse (3), standard library (tang)   
 ::
 ~%  %zuse  +  ~
+!:
 |%
   ::::::::::::::::::::::::::::::::::::::::::::::::::::::  ::
 ::::              chapter 3b, Arvo libraries            ::::
@@ -1010,7 +1011,7 @@
   ?-  -.mis
     %del  [%ins p.mis]
     %ins  [%del p.mis]
-    %dif  [%dif (limp p.mis)]
+    %dif  [%dif p.mis]                                  ::  XX  incorrect
     %mut  [%mut q.mis p.mis]
   ==
 ::
@@ -1048,28 +1049,6 @@
   ==
 ::
 ++  ze  !:
-  =+  ^=  silk
-      $&  [p=silk q=silk]
-      $%  [%bake p=mark q=beam r=path]
-          [%boil p=mark q=beam r=path]
-          [%call p=silk q=silk]
-          [%cast p=mark q=silk]
-          [%diff p=silk q=silk]
-          [%done p=(set beam) q=cage]
-          [%dude p=tank q=silk]
-          [%dune p=(set beam) q=(unit cage)]
-          [%mute p=silk q=(list (pair wing silk))]
-          [%pact p=silk q=silk]
-          [%plan p=beam q=spur r=hood]
-          [%reef ~]
-          [%ride p=twig q=silk]
-          [%vale p=mark q=ship r=*]
-      ==
-  =+  ^=  silk
-      $%  [%diff p=cage q=cage]
-          [%pact p=cage q=(list cage)]
-      ==
-  =|  mow=(list silk)
   |_  [lim=@da dome rang]
   ++  aeon-to-tako  ~(got by hit)
   ++  aeon-to-yaki  (cork aeon-to-tako tako-to-yaki)
@@ -1083,72 +1062,57 @@
   ::
   ++  tako-to-yaki  ~(got by hut)                       ::  grab yaki
   ++  lobe-to-blob  ~(got by lat)                       ::  grab blob
-  ++  lobe-to-noun                                      ::  grab blob
-    |=  p=lobe                                          ::  ^-  *
-    %-  blob-to-noun  
+  ++  lobe-to-cage                                      ::  grab blob
+    |=  p=lobe                                          ::  ^-  maybe cage
+    ^-  (each cage ,*)
+    %-  blob-to-cage  
     (lobe-to-blob p)
   ::
   ++  make-direct                                       ::  make blob
-    |=  [p=* q=umph]
+    |=  [p=cage]
     ^-  blob
-    [%direct (mug p) p q]
+    [%direct (mug p) p]
   ::
   ++  make-delta                                        ::  make blob delta
     |=  [p=lobe q=cage]
     ^-  blob
     =+  t=[%delta 0 p q]
-    =+  z=(blob-to-noun t)
+    =+  z=(blob-to-cage t)
     =+  ^=  has
         %^  cat  7  (sham [%blob z])
         (sham [%lobe z])
     [%delta has p q]
   ::
-  ++  blob-to-umph                                      ::  blob umph [prep]
-    |=  p=blob                                          ::  used in merge
-    ^-  umph
-    ?-   -.p
-       %delta  p.r.p
-       %direct  r.p
-       %indirect  p.r.p
-    ==
-  ::
-  ++  blob-to-noun                                      ::  grab blob
-    |=  p=blob
-    ?-   -.p
-       %delta  (lump r.p (lobe-to-noun q.p))
-       %direct  q.p
-       %indirect  q.p
-    ==
-  ::
-  ++  new-blob-to-cage
+  ++  blob-to-cage
     |=  p=blob
     ::  ^-  (each cage ,[cage this])
     ?-    -.p
       %direct    [%& q.p]
       %indirect  [%& q.p]
-      %delta     [%| r.p $(p q.p)]
+      %delta     [%| r.p $(p (lobe-to-blob q.p))]
     ==
   ::
   ::
   ++  diff-yakis                                        ::  fundamental diff
     |=  [p=yaki q=yaki]
     ^-  (map path miso)
-    %+  roll  (~(tap in (luth q.p q.q)) ~)
-    |=  [pat=path yeb=(map path miso)]
-    =+  leb=(~(get by q.p) pat)
-    =+  lob=(~(get by q.q) pat)
-    ?~  leb  (~(put by yeb) pat [%ins (lobe-to-noun (need lob))])
-    ?~  lob  (~(put by yeb) pat [%del (lobe-to-noun (need leb))])
-    ?:  =(u.leb u.lob)  yeb
-    =+  veq=(lobe-to-blob u.leb)
-    =+  voq=(lobe-to-blob u.lob)
-    %+  ~(put by yeb)  pat
-    :-  %dif  
-    ?:  &(?=(%delta -.voq) =(u.leb q.voq))              ::  avoid diff
-      r.voq
-    =+  zeq=(blob-to-noun veq)
-    =+  zoq=(blob-to-noun voq)
-    ((diff (blob-to-umph (lobe-to-blob u.leb))) zeq zoq)
+    !!
+    ::  %+  roll  (~(tap in (luth q.p q.q)) ~)
+    ::  |=  [pat=path yeb=(map path miso)]
+    ::  =+  leb=(~(get by q.p) pat)
+    ::  =+  lob=(~(get by q.q) pat)
+    ::  ?~  leb  (~(put by yeb) pat [%ins (lobe-to-cage (need lob))])
+    ::  ?~  lob  (~(put by yeb) pat [%del (lobe-to-cage (need leb))])
+    ::  ?:  =(u.leb u.lob)  yeb
+    ::  =+  veq=(lobe-to-blob u.leb)
+    ::  =+  voq=(lobe-to-blob u.lob)
+    ::  %+  ~(put by yeb)  pat
+    ::  :-  %dif  
+    ::  ?:  &(?=(%delta -.voq) =(u.leb q.voq))              ::  avoid diff
+    ::    r.voq
+    ::  =+  zeq=(blob-to-noun veq)
+    ::  =+  zoq=(blob-to-noun voq)
+    ::  ((diff (blob-to-umph (lobe-to-blob u.leb))) zeq zoq)
   ::
   ++  lobes-at-path                                     ::    lobes-at-path:ze
     |=  [yon=aeon pax=path]                             ::  data at path
@@ -1322,13 +1286,13 @@
         (~(put by bat) pat (lobe-to-blob gar))          ::  use original
     ^=  bar  ^-  (map path blob)
     %+  roll  lar
-    |=  [[pat=path mys=miso] bar=(map path blob)]
+    |=  [[pat=path mys=misu] bar=(map path blob)]
     ^+  bar
     ?-    -.mys
         %ins                                            ::  insert if not exist
       ?:  (~(has by bar) pat)  !!                       ::
       ?:  (~(has by hat) pat)  !!                       ::
-      (~(put by bar) pat (make-direct p.mys %c))        ::  TODO content type?
+      (~(put by bar) pat (make-direct p.mys))
         %del                                            ::  delete if exists
       ?.  |((~(has by hat) pat) (~(has by bar) pat))  !!
       (~(del by bar) pat)
@@ -1351,8 +1315,9 @@
     ^-  ankh
     %-  cosh
     ?~  pat
-      =+  zar=(lobe-to-noun bar)
-      ank(q [~ (sham zar) zar])
+      =+  zar=(lobe-to-cage bar)
+      ?>  ?=(%& -.zar)
+      ank(q [~ (sham `cage`p.zar) p.zar])
     =+  nak=(~(get by r.ank) i.pat)
     %=  ank
       r  %+  ~(put by r.ank)  i.pat 
@@ -1558,261 +1523,260 @@
                  ==
              ==
       ==
-  ++  qeal                                          ::  merge p,q
-    |*  [us=[ship desk] th=[ship desk] pat=path p=miso q=miso r=(list) con=?]
-    ^-  miso                                        ::  in case of conflict
-    ~|  %qeal-fail
-    ?>  ?=(%dif -.p)
-    ?>  ?=(%dif -.q)
-    ?>  ?=(%c -.q.p.p)
-    ?>  ?=(%c -.q.p.q)
-    =+  s=(clean p.q.p.p)
-    =+  t=(clean p.q.p.q)
-    :-  %dif
-    :-  %c  ::  todo is this p.p.p?
-    :-  %c
-    |-  ^-  (urge)
-    ::?~  s  ?:  (qual t)  t
-    ::       ~|  %qail-conflict  !!
-    ::?~  t  ?:  (qual s)  s
-    ::       ~|  %qail-conflict  !!
-    ?~  s  t
-    ?~  t  s
-    ?-    -.i.s
-        %&
-      ?-    -.i.t
-          %&
-        ?:  =(p.i.s p.i.t)
-          [i.s $(s t.s, t t.t, r (slag p.i.s r))]
-        ?:  (gth p.i.s p.i.t)
-          [i.t $(t t.t, p.i.s (sub p.i.s p.i.t), r (slag p.i.t r))]
-        [i.s $(s t.s, p.i.t (sub p.i.t p.i.s), r (slag p.i.s r))]
-          %|
-        ?:  =(p.i.s (lent p.i.t))
-          [i.t $(s t.s, t t.t, r (slag p.i.s r))]
-        ?:  (gth p.i.s (lent p.i.t))
-          :-  i.t 
-          $(t t.t, p.i.s (sub p.i.s (lent p.i.t)), r (slag (lent p.i.t) r))
-        ?.  con  ~|  %quil-conflict  !!           ::  conflict
-        ~&  [%quil-conflict-soft pat]
-        =+  mar=(match-conflict us th s t r)
-        [[%| p.mar] $(s p.q.mar, t q.q.mar, r r.q.mar)]
-      ==
-        %|
-      ?-    -.i.t
-          %|
-        ?.  con  ~|  %quil-conflict  !!
-        ~&  [%quil-conflict-soft pat]
-        =+  mar=(match-conflict us th s t r)
-        [[%| p.mar] $(s p.q.mar, t q.q.mar, r r.q.mar)]
-          %&
-        ?:  =(p.i.t (lent p.i.s))
-          [i.s $(s t.s, t t.t, r (slag p.i.t r))]
-        ?:  (gth p.i.t (lent p.i.s))
-          :-  i.s
-          $(s t.s, p.i.t (sub p.i.t (lent p.i.s)), r (slag (lent p.i.s) r))
-        ?.  con  ~|  %quil-conflict  !!
-        ~&  [%quil-conflict-soft pat]
-        =+  mar=(match-conflict us th s t r)
-        [[%| p.mar] $(s p.q.mar, t q.q.mar, r r.q.mar)]
-      ==
-    ==
-  ++  quil                                          ::  merge p,q
-    |=  $:  us=[ship desk]
-            th=[ship desk]
-            pat=path
-            p=(unit miso)
-            q=(unit miso)
-            r=(unit (list))
-            con=?
-        ==
-    ^-  (unit miso)
-    ?~  p  q                                        ::  trivial
-    ?~  q  p                                        ::  trivial
-    ?-  -.u.p
-      %ins  ?>  ?=(%ins -.u.q)
-            ?.  con  !!
-            %-  some
-            :-  %ins
-            %-  role
-            %-  annotate
-            :-  us 
-            :-  th
-            :-  (lore ((hard ,@) p.u.p)) 
-            :-  (lore ((hard ,@) p.u.q))
-            ~
-      %del  p
-      %dif  ?>  ?=(%dif -.u.q)
-            %-  some
-            %^  qeal  us  th
-            :^  pat  u.p  u.q                       ::  merge p,q
-            :-  %-  need  r
-            con
-    ==
-  ::
-  ++  meld                                          ::  merge p,q from r
-    |=  [p=yaki q=yaki r=yaki con=? us=[ship desk] th=[ship desk]]
-    ^-  (map path blob)
-    =+  s=(diff-yakis r p)
-    =+  t=(diff-yakis r q)
-    =+  lut=(luth s t)
-    %-  |=  res=(map path blob)                        ::  add old
-        ^-  (map path blob)
-        %-  ~(uni by res)
-        %-  mo
-        %+  turn  
-          %+  skip  (~(tap by q.r) ~)                  ::  loop through old
-          |=  [pat=path bar=lobe]  ^-  ?
-          (~(has in lut) pat)                          ::  skip updated
-        |=  [pat=path bar=lobe]  ^-  [path blob]
-        [pat (lobe-to-blob bar)]                       ::  lookup objects
-    %+  roll  (~(tap in (luth s t)) ~)
-    |=  [pat=path res=(map path blob)]
-    =+  ^=  v
-        %-  need
-        %^  quil  us  th
-        :-  pat
-        :+  (~(get by s) pat)
-          (~(get by t) pat)
-        :_  con
-        %-  %-  lift  lore
-        %-  %-  lift  %-  hard  ,@                     ::  for %c
-        %-  %-  lift  lobe-to-noun
-        %-  ~(get by q.r)
-        pat
-    ?-    -.v
-        %del  res                                      ::  no longer exists
-        %ins                                           ::  new file
-      %+  ~(put by res)  pat 
-      %+  make-direct  p.v  %c                         ::  TODO content type?
-        %dif                                           ::  patch from r
-      %+  ~(put by res)  pat
-      %-  make-direct
-      :_  %c
-      %+  lump  p.v
-      %-  lobe-to-noun
-      %-  ~(got by q.r)  pat
-    ==
-  ::
-  ::  merge types
-  ::
-  ++  mate                                          ::  merge p,q
-    |=  con=?                                       ::  %mate, %meld
-    |=  [p=yaki q=yaki us=[ship desk] th=[ship desk]]
-    ^-  (map path blob)
-    =+  r=(~(tap in (find-merge-points p q)) ~)
-    ?~  r
-      ~|(%mate-no-ancestor !!)
-    ?:  =(1 (lent r))
-      (meld p q i.r con us th)
-    ~|(%mate-criss-cross !!)
-  ::
-  ++  keep                                          ::  %this
-    |=  [p=yaki q=yaki [ship desk] [ship desk]]
-    ^-  (map path blob)
-    %+  roll  (~(tap by q.p) ~)
-    |=  [[pat=path lob=lobe] zar=(map path blob)]
-    ^-  (map path blob)
-    (~(put by zar) pat (lobe-to-blob lob))
-  ::
-  ++  drop                                          ::  %that
-    |=  [p=yaki q=yaki r=[ship desk] s=[ship desk]]
-    ^-  (map path blob)
-    (keep q p r s)
-  ::
-  ++  forge                                         ::  %forge
-    |=  [p=yaki q=yaki s=[ship desk] t=[ship desk]]
-    ^-  (map path blob)
-    =+  r=(~(tap in (find-merge-points p q)) ~)
-    ?~  r
-      ~|(%forge-no-ancestor !!)
-    %-  |=  [r=yaki lut=(map lobe blob) hat=(map tako yaki)]
-        =.  lat  lut
-        =.  hut  hat
-        (meld p q r & s t)                          ::  fake merge
-    %+  roll  t.r                                   ::  fake ancestor
-    |=  [par=yaki [for=_i.r lut=_lat hat=_hut]]
-    =.  lat  lut
-    =+  ^=  far
-        ^-  (map path lobe)
-        %-  ~(urn by (forge par for s t))
-        |=  [k=path v=blob]  (blob-to-lobe v)
-    =+  u=(make-yaki [r.par r.for ~] far `@da`0)    ::  fake yaki
-    :-  u
-    :_  (~(put by hat) r.u u)
-    =<  -
-    %-  update-lat
-    :_  ~
-    %-  ~(urn by q.u)
-    |=  [path k=lobe]
-    (lobe-to-blob k)
-  ::
-  ::  actual merge
-  ::
-  ++  merge
-    |=  [us=[ship desk] th=[ship desk]]
-    |=  [p=yaki q=yaki r=@da s=$+([yaki yaki [ship desk] [ship desk]] (map path blob))]
-    ^-  [yaki (map path blob)]
-    =+  u=(s p q us th)
-    =+  ^=  t
-        ^-  (map path lobe)
-        %+  roll  (~(tap by u) ~)
-        |=  [[pat=path bar=blob] yeb=(map path lobe)]
-        (~(put by yeb) pat (blob-to-lobe bar))
-    :_  u
-    (make-yaki [r.p r.q ~] t r)
-  ::
-  ++  strategy                                          ::  merge strategy
-    |=  gem=?(%meld %mate %that %this)
-    ?-  gem
-      %meld  (mate %.y)
-      %mate  (mate %.n)
-      %this  keep
-      %that  drop
-    ==
-  ::
-  ++  construct-merge                                   ::    construct-merge:ze
-    |=  [gem=germ who=ship des=desk sab=saba now=@da]   ::  construct merge
-    ^-  (unit (unit mizu))                              ::::::
-    =+  for=s.sab                                       ::  foreign dome
-    =+  mer=(merge [who des] [p.sab q.sab])
-    ?-  gem
-        %init                                           ::  force fine
-          ?.  =(let 0)                                  ::  hell no
-            !!
-          =+  hot=(~(put by *(map aeon tako)) 1 (~(got by hit.for) let.for))
-          [~ [~ [1 hot hut lat]]]                       ::  trivial
-        %fine
-          =+  der=(~(got by hit.for) let.for)
-          =+  owr=(~(got by hit) let)
-          ?:  =(der owr)
-            [~ ~]
-          ?:  (~(has in (reachable-takos owr)) der)
-            [~ ~]
-          ?.  (~(has in (reachable-takos der)) owr)
-            ~                                          ::  not a fast forward
-          ~&  [%merge-fine p.sab q.sab]
-          [~ [~ [+(let) (~(put by hit) +(let) der) hut lat]]]
-        ?(%mate %that %this %meld)
-          =+  foreign-head=(tako-to-yaki (~(got by hit.for) let.for))
-          =+  our-head=(tako-to-yaki (~(got by hit) let))
-          ?:  =(r.foreign-head r.our-head)
-            [~ ~]                                      ::  up to date
-          ?:  (~(has in (reachable-takos r.our-head)) r.foreign-head)
-            [~ ~]                                      ::  up to date
-          ?:  ?&  |(=(gem %mate) =(gem %meld))
-                  (~(has in (reachable-takos r.foreign-head)) r.our-head)
-              ==
-            $(gem %fine)                               ::  use fast forward
-          =+  gar=(mer our-head foreign-head now (strategy gem))
-          =+  yak=-.gar
-          =+  hek=+.gar
-          =.  lat  -:(update-lat hek ~)                ::  add new blobs
-          =.  hut  (~(put by *(map tako yaki)) r.yak yak)
-          =.  let  +(let)
-          =.  hit  (~(put by *(map aeon tako)) let r.yak)
-          [~ [~ [let hit hut lat]]]
-    ==
+  ::  ++  qeal                                          ::  merge p,q
+  ::    |*  [us=[ship desk] th=[ship desk] pat=path p=miso q=miso r=(list) con=?]
+  ::    ^-  miso                                        ::  in case of conflict
+  ::    ~|  %qeal-fail
+  ::    ?>  ?=(%dif -.p)
+  ::    ?>  ?=(%dif -.q)
+  ::    ?>  ?=(%c -.q.p.p)
+  ::    ?>  ?=(%c -.q.p.q)
+  ::    =+  s=(clean p.q.p.p)
+  ::    =+  t=(clean p.q.p.q)
+  ::    :-  %dif
+  ::    :-  %c  ::  todo is this p.p.p?
+  ::    :-  %c
+  ::    |-  ^-  (urge)
+  ::    ::?~  s  ?:  (qual t)  t
+  ::    ::       ~|  %qail-conflict  !!
+  ::    ::?~  t  ?:  (qual s)  s
+  ::    ::       ~|  %qail-conflict  !!
+  ::    ?~  s  t
+  ::    ?~  t  s
+  ::    ?-    -.i.s
+  ::        %&
+  ::      ?-    -.i.t
+  ::          %&
+  ::        ?:  =(p.i.s p.i.t)
+  ::          [i.s $(s t.s, t t.t, r (slag p.i.s r))]
+  ::        ?:  (gth p.i.s p.i.t)
+  ::          [i.t $(t t.t, p.i.s (sub p.i.s p.i.t), r (slag p.i.t r))]
+  ::        [i.s $(s t.s, p.i.t (sub p.i.t p.i.s), r (slag p.i.s r))]
+  ::          %|
+  ::        ?:  =(p.i.s (lent p.i.t))
+  ::          [i.t $(s t.s, t t.t, r (slag p.i.s r))]
+  ::        ?:  (gth p.i.s (lent p.i.t))
+  ::          :-  i.t 
+  ::          $(t t.t, p.i.s (sub p.i.s (lent p.i.t)), r (slag (lent p.i.t) r))
+  ::        ?.  con  ~|  %quil-conflict  !!           ::  conflict
+  ::        ~&  [%quil-conflict-soft pat]
+  ::        =+  mar=(match-conflict us th s t r)
+  ::        [[%| p.mar] $(s p.q.mar, t q.q.mar, r r.q.mar)]
+  ::      ==
+  ::        %|
+  ::      ?-    -.i.t
+  ::          %|
+  ::        ?.  con  ~|  %quil-conflict  !!
+  ::        ~&  [%quil-conflict-soft pat]
+  ::        =+  mar=(match-conflict us th s t r)
+  ::        [[%| p.mar] $(s p.q.mar, t q.q.mar, r r.q.mar)]
+  ::          %&
+  ::        ?:  =(p.i.t (lent p.i.s))
+  ::          [i.s $(s t.s, t t.t, r (slag p.i.t r))]
+  ::        ?:  (gth p.i.t (lent p.i.s))
+  ::          :-  i.s
+  ::          $(s t.s, p.i.t (sub p.i.t (lent p.i.s)), r (slag (lent p.i.s) r))
+  ::        ?.  con  ~|  %quil-conflict  !!
+  ::        ~&  [%quil-conflict-soft pat]
+  ::        =+  mar=(match-conflict us th s t r)
+  ::        [[%| p.mar] $(s p.q.mar, t q.q.mar, r r.q.mar)]
+  ::      ==
+  ::    ==
+  ::  ++  quil                                          ::  merge p,q
+  ::    |=  $:  us=[ship desk]
+  ::            th=[ship desk]
+  ::            pat=path
+  ::            p=(unit miso)
+  ::            q=(unit miso)
+  ::            r=(unit (list))
+  ::            con=?
+  ::        ==
+  ::    ^-  (unit miso)
+  ::    ?~  p  q                                        ::  trivial
+  ::    ?~  q  p                                        ::  trivial
+  ::    ?-  -.u.p
+  ::      %ins  ?>  ?=(%ins -.u.q)
+  ::            ?.  con  !!
+  ::            %-  some
+  ::            :-  %ins
+  ::            %-  role
+  ::            %-  annotate
+  ::            :-  us 
+  ::            :-  th
+  ::            :-  (lore ((hard ,@) p.u.p)) 
+  ::            :-  (lore ((hard ,@) p.u.q))
+  ::            ~
+  ::      %del  p
+  ::      %dif  ?>  ?=(%dif -.u.q)
+  ::            %-  some
+  ::            %^  qeal  us  th
+  ::            :^  pat  u.p  u.q                       ::  merge p,q
+  ::            :-  %-  need  r
+  ::            con
+  ::    ==
+  ::  ::
+  ::  ++  meld                                          ::  merge p,q from r
+  ::    |=  [p=yaki q=yaki r=yaki con=? us=[ship desk] th=[ship desk]]
+  ::    ^-  (map path blob)
+  ::    =+  s=(diff-yakis r p)
+  ::    =+  t=(diff-yakis r q)
+  ::    =+  lut=(luth s t)
+  ::    %-  |=  res=(map path blob)                        ::  add old
+  ::        ^-  (map path blob)
+  ::        %-  ~(uni by res)
+  ::        %-  mo
+  ::        %+  turn  
+  ::          %+  skip  (~(tap by q.r) ~)                  ::  loop through old
+  ::          |=  [pat=path bar=lobe]  ^-  ?
+  ::          (~(has in lut) pat)                          ::  skip updated
+  ::        |=  [pat=path bar=lobe]  ^-  [path blob]
+  ::        [pat (lobe-to-blob bar)]                       ::  lookup objects
+  ::    %+  roll  (~(tap in (luth s t)) ~)
+  ::    |=  [pat=path res=(map path blob)]
+  ::    =+  ^=  v
+  ::        %-  need
+  ::        %^  quil  us  th
+  ::        :-  pat
+  ::        :+  (~(get by s) pat)
+  ::          (~(get by t) pat)
+  ::        :_  con
+  ::        %-  %-  lift  lore
+  ::        %-  %-  lift  %-  hard  ,@                     ::  for %c
+  ::        %-  %-  lift  lobe-to-cage
+  ::        %-  ~(get by q.r)
+  ::        pat
+  ::    ?-    -.v
+  ::        %del  res                                      ::  no longer exists
+  ::        %ins                                           ::  new file
+  ::      %+  ~(put by res)  pat 
+  ::      (make-direct p.v)
+  ::        %dif                                           ::  patch from r
+  ::      %+  ~(put by res)  pat
+  ::      %-  make-direct
+  ::      %+  lump  p.v
+  ::      %-  lobe-to-cage
+  ::      %-  ~(got by q.r)  pat
+  ::    ==
+  ::  ::
+  ::  ::  merge types
+  ::  ::
+  ::  ++  mate                                          ::  merge p,q
+  ::    |=  con=?                                       ::  %mate, %meld
+  ::    |=  [p=yaki q=yaki us=[ship desk] th=[ship desk]]
+  ::    ^-  (map path blob)
+  ::    =+  r=(~(tap in (find-merge-points p q)) ~)
+  ::    ?~  r
+  ::      ~|(%mate-no-ancestor !!)
+  ::    ?:  =(1 (lent r))
+  ::      (meld p q i.r con us th)
+  ::    ~|(%mate-criss-cross !!)
+  ::  ::
+  ::  ++  keep                                          ::  %this
+  ::    |=  [p=yaki q=yaki [ship desk] [ship desk]]
+  ::    ^-  (map path blob)
+  ::    %+  roll  (~(tap by q.p) ~)
+  ::    |=  [[pat=path lob=lobe] zar=(map path blob)]
+  ::    ^-  (map path blob)
+  ::    (~(put by zar) pat (lobe-to-blob lob))
+  ::  ::
+  ::  ++  drop                                          ::  %that
+  ::    |=  [p=yaki q=yaki r=[ship desk] s=[ship desk]]
+  ::    ^-  (map path blob)
+  ::    (keep q p r s)
+  ::  ::
+  ::  ++  forge                                         ::  %forge
+  ::    |=  [p=yaki q=yaki s=[ship desk] t=[ship desk]]
+  ::    ^-  (map path blob)
+  ::    =+  r=(~(tap in (find-merge-points p q)) ~)
+  ::    ?~  r
+  ::      ~|(%forge-no-ancestor !!)
+  ::    %-  |=  [r=yaki lut=(map lobe blob) hat=(map tako yaki)]
+  ::        =.  lat  lut
+  ::        =.  hut  hat
+  ::        (meld p q r & s t)                          ::  fake merge
+  ::    %+  roll  t.r                                   ::  fake ancestor
+  ::    |=  [par=yaki [for=_i.r lut=_lat hat=_hut]]
+  ::    =.  lat  lut
+  ::    =+  ^=  far
+  ::        ^-  (map path lobe)
+  ::        %-  ~(urn by (forge par for s t))
+  ::        |=  [k=path v=blob]  (blob-to-lobe v)
+  ::    =+  u=(make-yaki [r.par r.for ~] far `@da`0)    ::  fake yaki
+  ::    :-  u
+  ::    :_  (~(put by hat) r.u u)
+  ::    =<  -
+  ::    %-  update-lat
+  ::    :_  ~
+  ::    %-  ~(urn by q.u)
+  ::    |=  [path k=lobe]
+  ::    (lobe-to-blob k)
+  ::  ::
+  ::  ::  actual merge
+  ::  ::
+  ::  ++  merge
+  ::    |=  [us=[ship desk] th=[ship desk]]
+  ::    |=  [p=yaki q=yaki r=@da s=$+([yaki yaki [ship desk] [ship desk]] (map path blob))]
+  ::    ^-  [yaki (map path blob)]
+  ::    =+  u=(s p q us th)
+  ::    =+  ^=  t
+  ::        ^-  (map path lobe)
+  ::        %+  roll  (~(tap by u) ~)
+  ::        |=  [[pat=path bar=blob] yeb=(map path lobe)]
+  ::        (~(put by yeb) pat (blob-to-lobe bar))
+  ::    :_  u
+  ::    (make-yaki [r.p r.q ~] t r)
+  ::  ::
+  ::  ++  strategy                                          ::  merge strategy
+  ::    |=  gem=?(%meld %mate %that %this)
+  ::    ?-  gem
+  ::      %meld  (mate %.y)
+  ::      %mate  (mate %.n)
+  ::      %this  keep
+  ::      %that  drop
+  ::    ==
+  ::  ::
+  ::  ++  construct-merge                                   ::    construct-merge:ze
+  ::    |=  [gem=germ who=ship des=desk sab=saba now=@da]   ::  construct merge
+  ::    ^-  (unit (unit mizu))                              ::::::
+  ::    =+  for=s.sab                                       ::  foreign dome
+  ::    =+  mer=(merge [who des] [p.sab q.sab])
+  ::    ?-  gem
+  ::        %init                                           ::  force fine
+  ::          ?.  =(let 0)                                  ::  hell no
+  ::            !!
+  ::          =+  hot=(~(put by *(map aeon tako)) 1 (~(got by hit.for) let.for))
+  ::          [~ [~ [1 hot hut lat]]]                       ::  trivial
+  ::        %fine
+  ::          =+  der=(~(got by hit.for) let.for)
+  ::          =+  owr=(~(got by hit) let)
+  ::          ?:  =(der owr)
+  ::            [~ ~]
+  ::          ?:  (~(has in (reachable-takos owr)) der)
+  ::            [~ ~]
+  ::          ?.  (~(has in (reachable-takos der)) owr)
+  ::            ~                                          ::  not a fast forward
+  ::          ~&  [%merge-fine p.sab q.sab]
+  ::          [~ [~ [+(let) (~(put by hit) +(let) der) hut lat]]]
+  ::        ?(%mate %that %this %meld)
+  ::          =+  foreign-head=(tako-to-yaki (~(got by hit.for) let.for))
+  ::          =+  our-head=(tako-to-yaki (~(got by hit) let))
+  ::          ?:  =(r.foreign-head r.our-head)
+  ::            [~ ~]                                      ::  up to date
+  ::          ?:  (~(has in (reachable-takos r.our-head)) r.foreign-head)
+  ::            [~ ~]                                      ::  up to date
+  ::          ?:  ?&  |(=(gem %mate) =(gem %meld))
+  ::                  (~(has in (reachable-takos r.foreign-head)) r.our-head)
+  ::              ==
+  ::            $(gem %fine)                               ::  use fast forward
+  ::          =+  gar=(mer our-head foreign-head now (strategy gem))
+  ::          =+  yak=-.gar
+  ::          =+  hek=+.gar
+  ::          =.  lat  -:(update-lat hek ~)                ::  add new blobs
+  ::          =.  hut  (~(put by *(map tako yaki)) r.yak yak)
+  ::          =.  let  +(let)
+  ::          =.  hit  (~(put by *(map aeon tako)) let r.yak)
+  ::          [~ [~ [let hit hut lat]]]
+  ::    ==
   ::
   ++  read                                              ::    read:ze
     |=  mun=mood                                        ::  read at point
@@ -1848,7 +1812,7 @@
     |=  [pat=path lob=lobe]
     =+  zat=(~(get by q) pat)
     ?~  zat  %.n
-    =((lobe-to-noun u.zat) (lobe-to-noun lob))
+    =((lobe-to-cage u.zat) (lobe-to-cage lob))
   ::
   ++  edit                                              ::    edit:ze
     |=  [wen=@da lem=nuri]                              ::  edit
@@ -1868,7 +1832,8 @@
              hit  (~(put by hit) +(let) r.yak)
              hut  (~(put by hut) r.yak yak)
          ==
-         +>.$(ank (checkout-ankh q.yak))
+         +>.$
+         ::  +>.$(ank (checkout-ankh q.yak))
       |  +>.$(lab ?<((~(has by lab) p.lem) (~(put by lab) p.lem let)))
     ==
   --
@@ -1954,60 +1919,58 @@
     =.  +.^$  rm-r:(descend p.i.dyr)
     $(dyr t.dyr)
   ::
-  ++  drum                                              ::  apply effect
-    |=  [pax=path mis=miso]                             ::  XX unused (++dune)
-    ^+  +>
-    ?^  pax
-      update-hash:(ascend:$(pax t.pax, +> (descend i.pax)) i.pax ank)
-    ~|  %clay-fail
-    ?-    -.mis
-        %del
-      ?>  &(?=(^ q.ank) =(q.u.q.ank p.mis))
-      +>.$(p.ank (mix p.u.q.ank p.ank), q.ank ~)
-    ::
-        %ins
-      ?>  ?=(~ q.ank)
-      =+  sam=(sham p.mis)
-      +>.$(p.ank (mix sam p.ank), q.ank [~ sam p.mis])
-    ::
-        %dif
-      ?>  ?=(^ q.ank)
-      =+  nex=(lump p.mis q.u.q.ank)
-      =+  sam=(sham nex)
-      +>.$(p.ank :(mix sam p.u.q.ank p.ank), q.ank [~ sam nex])
-    ==
-  ::
-  ++  dune                                              ::  apply
-    |-  ^+  +                                           ::  XX unused (++durn)
-    ?~  myz  +
-    =>  .(+ (drum p.i.myz q.i.myz))
-    $(myz ?>(?=(^ myz) t.myz))
-  ::
-  ++  durn                                              ::  apply forward
-    |=  nyp=soba                                        ::  XX unused
-    ^+  +>
-    ?:  =([0 0] p.nyp)
-      dune(myz q.nyp)
-    =>  ?:  =(p.ank p.p.nyp)  .
-        ~&  [%durn-in-wrong p.ank p.p.nyp]
-        .
-    =.  +>  dune(myz q.nyp)
-    =>  ?:  =(p.ank q.p.nyp)  .
-        ~&  [%durn-out-wrong p.ank q.p.nyp]
-        .
-    +>
+  ::++  drum                                              ::  apply effect
+  ::  |=  [pax=path mis=miso]                             ::  XX unused (++dune)
+  ::  ^+  +>
+  ::  ?^  pax
+  ::    update-hash:(ascend:$(pax t.pax, +> (descend i.pax)) i.pax ank)
+  ::  ~|  %clay-fail
+  ::  ?-    -.mis
+  ::      %del
+  ::    ?>  &(?=(^ q.ank) =(q.u.q.ank p.mis))
+  ::    +>.$(p.ank (mix p.u.q.ank p.ank), q.ank ~)
+  ::  ::
+  ::      %ins
+  ::    ?>  ?=(~ q.ank)
+  ::    =+  sam=(sham p.mis)
+  ::    +>.$(p.ank (mix sam p.ank), q.ank [~ sam p.mis])
+  ::  ::
+  ::      %dif
+  ::    ?>  ?=(^ q.ank)
+  ::    =+  nex=(lump p.mis q.u.q.ank)
+  ::    =+  sam=(sham nex)
+  ::    +>.$(p.ank :(mix sam p.u.q.ank p.ank), q.ank [~ sam nex])
+  ::  ==
+  ::::
+  ::++  dune                                              ::  apply
+  ::  |-  ^+  +                                           ::  XX unused (++durn)
+  ::  ?~  myz  +
+  ::  =>  .(+ (drum p.i.myz q.i.myz))
+  ::  $(myz ?>(?=(^ myz) t.myz))
+  ::::
+  ::++  durn                                              ::  apply forward
+  ::  |=  nyp=soba                                        ::  XX unused
+  ::  ^+  +>
+  ::  ?:  =([0 0] p.nyp)
+  ::    dune(myz q.nyp)
+  ::  =>  ?:  =(p.ank p.p.nyp)  .
+  ::      ~&  [%durn-in-wrong p.ank p.p.nyp]
+  ::      .
+  ::  =.  +>  dune(myz q.nyp)
+  ::  =>  ?:  =(p.ank q.p.nyp)  .
+  ::      ~&  [%durn-out-wrong p.ank q.p.nyp]
+  ::      .
+  ::  +>
   --
 ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 ::                section 3bF, filesystem interface     ::
 ::
 ++  feel                                                ::  simple file write
-  |=  [pax=path val=*]
+  |=  [pax=path val=cage]
   ^-  miso
   =+  dir=((hard arch) .^(%cy pax))
   ?~  q.dir  [%ins val]
-  :-  %dif
-  ^-  udon
-  [%a %a .^(%cx pax) val]
+  [%mut ((hard cage) .^(%cx pax)) val]
 ::
 ++  file                                                ::  simple file load
   |=  pax=path
@@ -2016,7 +1979,7 @@
   ?~(q.dir ~ [~ .^(%cx pax)])
 ::
 ++  foal                                                ::  high-level write
-  |=  [pax=path val=*]
+  |=  [pax=path val=cage]
   ^-  toro
   ?>  ?=([* * * *] pax)
   [i.t.pax [%& [*cart [[t.t.t.pax (feel pax val)] ~]]]]
@@ -2025,7 +1988,7 @@
   |=  pax=path
   ^-  toro
   ?>  ?=([* * * *] pax)
-  [i.t.pax [%& [*cart [[t.t.t.pax [%del .^(%cx pax)]] ~]]]]
+  [i.t.pax [%& [*cart [[t.t.t.pax [%del %$ !>(.^(%cx pax))]] ~]]]]
 ::
 ++  furl                                                ::  unify changes
   |=  [one=toro two=toro]
@@ -2034,7 +1997,7 @@
   ?>  ?&  =(p.one p.two)                                ::  same path
           &(?=(& -.q.one) ?=(& -.q.two))                ::  both deltas
       ==
-  [p.one [%& [*cart (weld q.q.q.one q.q.q.two)]]]
+  [p.one [%& [*cart (weld q.p.q.one q.p.q.two)]]]
 ::
 ++  meat                                                ::  kite to .^ path
   |=  kit=kite
@@ -2756,6 +2719,9 @@
               [%direct p=lobe q=cage]                   ::
               [%indirect p=lobe q=cage r=cage s=lobe]   ::
           ==                                            ::
+++  blub  $%  [%direct p=lobe q=cage]                   ::
+              [%indirect p=lobe q=cage r=cage s=lobe]   ::
+          ==                                            ::
 ++  boat  ,[(list slip) tart]                           ::  user stage
 ++  boon                                                ::  fort output
           $%  [%beer p=ship q=@uvG]                     ::  gained ownership