RIGHT_BETA

Drule.RIGHT_BETA : (thm -> thm)

Beta-reduces a top-level beta-redex on the right-hand side of an equation.

When applied to an equational theorem, RIGHT_BETA applies beta-reduction at top level to the right-hand side (only). Variables are renamed if necessary to avoid free variable capture.

    A |- s = (\x. t1) t2
   ----------------------  RIGHT_BETA
     A |- s = t1[t2/x]

Failure

Fails unless the theorem is equational, with its right-hand side being a top-level beta-redex.

See also

Thm.BETA_CONV, Conv.BETA_RULE, Tactic.BETA_TAC, Drule.RIGHT_LIST_BETA