COMB2_CONV

Conv.COMB2_CONV : conv * conv -> conv

Applies two conversions to an application’s subterms.

A call to COMB2_CONV(c1,c2) t, when t is an application term of the form f x, causes conversion c1 to be applied to term f, and conversion c2 to be applied to term x. If the results of these calls are theorems of the form |- f = f’ and |- x = x’, then the result of the call to COMB2_CONV is the theorem |- f x = f’ x’.

If one of the two sub-calls raises the UNCHANGED exception, then the result of that call is taken to be the reflexive theorem (|- x = x if c2 raises the exception, for example). If both conversions raise the UNCHANGED exception, then so too does COMB2_CONV(c1,c2) t.

Failure

Fails if the term is not a combination term, or if either conversion fails when applied to the respective sub-terms.

Example

> COMB2_CONV (ALL_CONV, numLib.REDUCE_CONV) ``f (10 * 3)``;
<<HOL message: inventing new type variable names: 'a>>
val it = |- f (10 * 3) = f 30 : thm

See also

Conv.ABS_CONV, Conv.COMB_CONV, Conv.FORK_CONV, Conv.RAND_CONV, Conv.RATOR_CONV