when pulling type out of term about to be eta expanded, substitute any type variables within the types of the extracted lambda vars
when pulling type out of term about to be eta expanded, substitute any type variables within the types of the extracted lambda vars

darcs-hash:96d44046c7fcff081d2d9a53004bb2b72fd98766

dpwright/jhc,dpwright/jhc,dpwright/jhc,dpwright/jhc