NOTE-2-8-PROOF-CHECKER.html -- ACL2 Version 6.3

### NOTE-2-8-PROOF-CHECKER

ACL2 Version 2.8 Notes on Proof-checker Changes

    Major Section:  NOTE-2-8

Added new proof-checker commands `wrap1`, `wrap`, and `wrap-induct`. `Wrap` replaces multiple goals by their conjunction: `(wrap instr1 instr2 ...)` employs `wrap1` so that the indicated instructions create only at most one new goal. `Wrap-induct` is a simple example of the use of `wrap`, so that induction creates only one goal (the conjunction of the base and induction steps). `Wrap1` can be used immediately after a prover call (`bash`, `prove`, `reduce`, `bdd`, or `induct`) to collapse the new goals into one. See proof-checker-commands.

The proof-checker command `=` failed to work as expected when a governing `IF`-test of the current term is T. This has been fixed (by fixing source function `conjuncts-of`). Thanks to Yoann Padioleau for bringing this problem to our attention.

The `type-alist` command now takes optional arguments that control whether or not the governors and/or conclusion are used in computing the context that is printed (see proof-checker-commands, specifically subtopic `type-alist`). Thanks to Rob Sumners for suggesting this improvement.

The macro `toggle-pc-macro` has always taken an optional second argument of `atomic-macro` or `macro`. However, this was not clearly documented, and those two symbols had to be in the `ACL2` package. Both of these problems have been remedied. Thanks to John Erickson for bringing the lack of documentation of the second argument to our attention.