@@ -26,7 +26,7 @@ At this point, there are three types of command which can be executed:
26261. relational algebra expressions such as:
2727
2828 ```
29−TutorialD: :s S join P
29+TutorialD (master): :showExpr S join P
3030┌──────┬─────┬──┬─────┬──┬─────┬──────┬──────┐
3131│CITY │COLOR│P#│PNAME│S#│SNAME│STATUS│WEIGHT│
3232├──────┼─────┼──┼─────┼──┼─────┼──────┼──────┤
@@ -43,26 +43,76 @@ TutorialD: :s S join P
4343└──────┴─────┴──┴─────┴──┴─────┴──────┴──────┘
4444```
4545
46− where ":s" instructs the interpreter to show the resultant relation, "S" and "P" are relation names, and "join" is the join operator.
46+ where ":show" instructs the interpreter to show the resultant relation, "S" and "P" are relation names, and "join" is the join operator.
47472. interpreter-level queries such as:
4848
4949 ```
50−TutorialD: :t S
50+TutorialD (master): :type S
5151{CITY "char", S# "char", SNAME "char", STATUS "char"}
5252```
5353
5454 which shows the Tutorial D type for a relational expression and
5555
5656 ```
57−TutorialD: :c
57+TutorialD (master): :constraints
5858fromList []
5959```
6060which displays database constraints.
6161
62+ ```
63+TutorialD (master): :commit
64+```
65+which commits the current "disconnected" transaction which is similar to the git staging area/index.
66+
67+ ```
68+TutorialD (master): :jumphead master
69+Done.
70+```
71+which changes the current disconnected transaction to reference another head.
72+
73+ ```
74+TutorialD (master): :jump 4a4ee715-297d-49db-bfd1-afaefadc902b
75+Done.
76+```
77+which resets the current "disconnected" transaction to refer to the committed transaction specified by the UUID.
78+
79+ ```
80+TutorialD (master): :branch devel
81+Done.
82+```
83+
84+which creates a new head named "devel" in the transaction graph and resets the current "disconnected" transaction to refer to the
85+
86+ ```
87+TutorialD (devel): :rollback
88+Done.
89+```
90+
91+which resets the current "disconnected" transaction to discard any collected changes.
92+
93+ ```
94+TutorialD (devel): :showGraph
95+┌───────┬────────────────────────────────────┬──────────────────────────────────────┐
96+│current│id │parents │
97+├───────┼────────────────────────────────────┼──────────────────────────────────────┤
98+│1 │1d064d54-cd2a-4a43-822a-cbd18cf7c4e8│┌────────────────────────────────────┐│
99+│ │ ││id ││
100+│ │ │├────────────────────────────────────┤│
101+│ │ ││4a4ee715-297d-49db-bfd1-afaefadc902b││
102+│ │ │└────────────────────────────────────┘│
103+│0 │4a4ee715-297d-49db-bfd1-afaefadc902b│┌──┐ │
104+│ │ ││id│ │
105+│ │ │ │
106+│ │ │└──┘ │
107+└───────┴────────────────────────────────────┴──────────────────────────────────────┘
108+```
109+
110+which displays all committed transactions and their parents. The "current" attribute indicates to which transactions the current "disconnected" transaction refers.
111+
621123. expressions which modify the database context such as:
63113
64114 ```
65−TutorialD: x := S JOIN P
115+TutorialD (master): x := S JOIN P
66116```
67117 which sets the relational variable named "x" to the results of "S join P" if the database constraint checking succeeds.
68118