split_pair_case_tac

bossLib.split_pair_case_tac : tactic

Splits pairs that are arguments to a pair-case expression.

A call to split_pair_case_tac will search the goal (starting with the conclusion and moving onto each assumption in turn), for a sub-term of the form case p of (x,y,...) => e, where the variables appearing in p are free in the goal. The tactic will then introduce a new assumption in the goal of the form

   p = (x,y,...)

where the variables x, y etc., are chosen to be as close as possible to the names in the case expression. In other words, they will vary only if those names are already free in the goal.

Failure

Fails if there is no such sub-term.

Example

> split_pair_case_tac ([], ``(case p of (x,y,z) => x + y * z) > 10``);
val it =
   ([([``p = (x,y,z)``], ``(case p of (x,y,z) => x + y * z) > 10``)], fn)

See also

bossLib.pairarg_tac, pairLib.Pair_Cases_on