REPEAT_TCL : thm_tactical -> thm_tactical

SYNOPSIS

Repeatedly applies a theorem-tactical until it fails when applied to the theorem.

DESCRIPTION

When applied to a theorem-tactical, a theorem-tactic and a theorem:

   REPEAT_TCL ttl ttac th

REPEAT_TCL repeatedly modifies the theorem according to ttl until it fails when given to the theorem-tactic ttac.

FAILURE CONDITIONS

Fails iff the theorem-tactic fails immediately when applied to the theorem.

EXAMPLE

It is often desirable to repeat the action of basic theorem-tactics. For example CHOOSE_THEN strips off a single existential quantification, so one might use REPEAT_TCL CHOOSE_THEN to get rid of them all. Alternatively, one might want to repeatedly break apart a theorem which is a nested conjunction and apply the same theorem-tactic to each conjunct. For example the following goal:

  # g `(0 = w /\ 0 = x) /\ 0 = y /\ 0 = z ==> w + x + y + z = 0`;;
  Warning: Free variables in goal: w, x, y, z
  val it : goalstack = 1 subgoal (1 total)

  `(0 = w /\ 0 = x) /\ 0 = y /\ 0 = z ==> w + x + y + z = 0`

might be solved by

  # e(DISCH_THEN (REPEAT_TCL CONJUNCTS_THEN (SUBST1_TAC o SYM)) THEN
      REWRITE_TAC[ADD_CLAUSES]);;

SEE ALSO

REPEAT_GTCL, THEN_TCL.