trvar for A.SimpleVar has come to uses TL.simpleVar
trvar for A.FieldVar has come to uses TL.fieldVar.
trvar for A.SubscriptVar has come to uses TL.subscriptVar.
new result.
new result.
new result.
test3b, additional test to detect a bug.

the type checker should not detect an error, but current version does.
fixed a bug that was detected by test3b.tig.
imported a latest bug-fix from chap6/.
trexp for A.RecordExp (Record Creation).