Q.MATCH_ASMSUB_RENAME

STRUCTURE

SYNOPSIS

Finds a match for a pattern in assumptions; instantiates goal to rename or abbreviate.

DESCRIPTION

When applied to the goal (asl,w), the tactic Q.MATCH_ASMSUB_RENAME_TAC q parses the quotation q in the context of the goal, producing a term pat to use as a pattern. The tactic then attempts a (first order) match of pat against each term in asl, stopping when it finds an assumption that either matches pat in its entirety, or has a sub-term that matches pat (holding existing free variables from the goal constant).

In either case, the match will return an instantiation mapping the fresh free variables of pat to terms occurring in the goal. This instantiation drops its bindings for variables whose names begin with an underscore, is next reversed, and is finally applied to the goal. This will both cause free variables in the goal to be renamed, and for larger terms to be replaced by variables (similar to what happens with the use of SPEC_TAC).

FAILURE

Fails if there is no valid match for the pattern among the assumptions and their sub-terms. A valid match will not bind variables that are bound in the assumption being searched.

EXAMPLE

In the following example, the variable x is treated as if a constant, so the search for a match with the pattern does not succeed on the first assumption (featuring P). Instead the second assumption provides the instantiation, and so the variable z in the original is renamed to n.

   > Q.MATCH_ASMSUB_RENAME_TAC `x < n`
       ([``P(y < m):bool``, ``Q(x < z) : bool``], ``x + z < 10``);
   val it = ([([``P (y < m)``, ``Q (x < n)``], ``x + n < 10``)],
             fn): goal list * validation

SEEALSO

MATCH_ASSUM_RENAME_TAC, MATCH_GOALSUB_RENAME_TAC