Fix some syntaxes uses of switch +: to _:

book/BBT.has.linear.kind2

@@ -10,7 +10,7 @@ BBT.has.linear
   use bin = λsize λnode_key λval λlft λrgt
     use P = λx
       ∀(cmp: ∀(a: K) ∀(b: K) Cmp)
-      ∀(size: #U60)
+      ∀(size: U60)
       ∀(node_key: K)
       ∀(val: V)
       ∀(lft: (BBT K V))

book/Kind.Term.show.go.kind2

@@ -140,7 +140,7 @@ Kind.Term.show.go
                 z
                 dep
                 (Kind.Text.show.go
-                  "; +: "
+                  "; _: "
                   (Kind.Term.show.go
                     (s (Kind.var (String.concat nam "-1") dep))
                     (Nat.succ dep)

book/Kind.reduce.mat.kind2

@@ -12,7 +12,7 @@ Kind.reduce.mat
   use Y = λx.val
     switch x = x.val {
       0: λz λs (Kind.reduce maj z)
-      +: λz λs (Kind.reduce maj (s (Kind.num x-1))) 
+      _: λz λs (Kind.reduce maj (s (Kind.num x-1))) 
     }: ∀(z: Kind.Term) ∀(s: ∀(x: Kind.Term) Kind.Term)
     Kind.Term
   use N = λx λz λs (Kind.mat nam x z s p)

book/QBool.kind2

@@ -8,9 +8,9 @@ QBool
     ∀(x: 
       switch t = t {
         0: (P QBool.true)
-        +: switch t = t-1 {
+        _: switch t = t-1 {
           0: (P QBool.false)
-          +: ∀(x: Empty) * 
+          _: ∀(x: Empty) * 
         }: * 
       }: *
     )

book/QBool.match.kind2

@@ -10,15 +10,15 @@ QBool.match
     λtag
     switch tag = tag {
       0: λx (x t)
-      +: λx
+      _: λx
       (switch tag_1 = tag-1 {
         0: λx (x f)
-        +: λx (x λe (Empty.absurd e *)) 
+        _: λx (x λe (Empty.absurd e *)) 
       }: ∀(x: 
         ∀(x: 
           switch tag_1 = tag_1 {
             0: (P QBool.false)
-            +: ∀(x: Empty) * 
+            _: ∀(x: Empty) * 
           }: *
         )
         (P a)
@@ -30,9 +30,9 @@ QBool.match
       ∀(x: 
         switch tag = tag {
           0: (P QBool.true)
-          +: switch tag_1 = tag-1 {
+          _: switch tag_1 = tag-1 {
             0: (P QBool.false)
-            +: ∀(x: Empty) * 
+            _: ∀(x: Empty) * 
           }: * 
         }: *
       )

book/QBool2.kind2

@@ -6,9 +6,9 @@ QBool2
     ∀(tag: U60)
     switch tag = tag {
       0: (P QBool2.true)
-      +: switch tag_1 = tag-1 {
+      _: switch tag_1 = tag-1 {
         0: (P QBool2.false)
-        +: ∀(e: Empty) * 
+        _: ∀(e: Empty) * 
       }: * 
     }: *
   )

book/QBool2.match.kind2

@@ -10,18 +10,18 @@ QBool2.match
     λtag
     switch tag = tag {
       0: t
-      +: switch tag_1 = tag-1 {
+      _: switch tag_1 = tag-1 {
         0: f
-        +: λe (~e λx *) 
+        _: λe (~e λx *) 
       }: switch tag_1 = tag_1 {
         0: (P QBool2.false)
-        +: ∀(e: Empty) * 
+        _: ∀(e: Empty) * 
       }: * 
     }: switch tag = tag {
       0: (P QBool2.true)
-      +: switch tag_1 = tag-1 {
+      _: switch tag_1 = tag-1 {
         0: (P QBool2.false)
-        +: ∀(e: Empty) * 
+        _: ∀(e: Empty) * 
       }: * 
     }: *
   )

book/QUnit.kind2

@@ -7,6 +7,6 @@ QUnit
     λtag
     switch tag = tag {
       0: ∀(one: (P QUnit.one)) (P self)
-      +: Empty 
+      _: Empty 
     }: *
   )

book/U60.equal.kind2

@@ -3,5 +3,5 @@ U60.equal
 = λa λb
   switch x = (== a b) {
     0: Bool.false
-    +: Bool.true 
+    _: Bool.true 
   }: Bool

book/U60.if.kind2

@@ -1,3 +1,3 @@
 U60.if
 : ∀(x: U60) ∀(P: *) ∀(t: P) ∀(f: P) P
-= λx λP λt λf switch x = x { 0: t +: f }: P
+= λx λP λt λf switch x = x { 0: t _: f }: P

book/U60.match.kind2

@@ -5,4 +5,4 @@ U60.switch
   ∀(z: (P 0))
   (P x)
 = λx λP λs λz
-  switch self = x { 0: z +: (s self-1) }: (P self)
+  switch self = x { 0: z _: (s self-1) }: (P self)

book/U60.name.go.kind2

@@ -3,7 +3,7 @@ U60.name.go
 = λn
   switch n = n {
     0: λnil nil
-    +: λnil
+    _: λnil
     (String.cons
       (+ 97 (% n-1 26))
       (U60.name.go (/ n-1 26) nil)

book/U60.show.go.kind2

@@ -7,5 +7,5 @@ U60.show.go
       (/ n 10)
       (String.cons (+ 48 (% n 10)) nil)
     )
-    +: λnil (String.cons (+ 48 n) nil) 
+    _: λnil (String.cons (+ 48 n) nil) 
   }: String.Concatenator

book/U60.to_bool.kind2

@@ -1,5 +1,5 @@
 U60.to_bool (x: U60) : Bool =
   switch x {
     0: Bool.false
-    +: Bool.true
+    _: Bool.true
   }: Bool