ALPHA_CONV

Drule.ALPHA_CONV : term -> conv

Renames the bound variable of a lambda-abstraction.

If x is a variable of type ty and M is an abstraction (with bound variable y of type ty and body t), then ALPHA_CONV x M returns the theorem:

   |- (\y.t) = (\x'. t[x'/y])

where the variable x':ty is a primed variant of x chosen so as not to be free in \y.t.

Failure

ALPHA_CONV x tm fails if x is not a variable, if tm is not an abstraction, or if x is a variable v and tm is a lambda abstraction \y.t but the types of v and y differ.

See also

Thm.ALPHA, Drule.GEN_ALPHA_CONV