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pairarg_tac                                                  (bossLib)
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pairarg_tac : tactic

SYNOPSIS
Adds a “splitting” equation for a pair term to goal assumptions.

KEYWORDS


DESCRIBE
A call to {pairarg_tac} will search the goal (starting with the
conclusion and moving onto each assumption in turn), for a sub-term of
the form {(\(x,y,...). body) arg}, where the variables appearing in
{arg} are free in the goal. The tactic will then introduce a new
assumption in the goal of the form

   arg = (x,y,...)

where the variables {x}, {y} etc., are chosen to be as close as
possible to the names in the paired abstraction. 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

> pairarg_tac ([], ``(\(x,y). x + y) p = 10``);
val it = ([([``p = (x,y)``], ``(\(x,y). x + y) p = 10``)], fn)


SEEALSO
pairLib.PairCases_on, bossLib.split_pair_case_tac.

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