let t1 = CicMetaSubst.apply_subst subst t1 in
let t2 = CicMetaSubst.apply_subst subst t2 in
let ty = CicMetaSubst.apply_subst subst ty in
+ let pbo = CicMetaSubst.apply_subst subst pbo in
+ let pty = CicMetaSubst.apply_subst subst pty in
let equality = CicMetaSubst.apply_subst subst equality in
let abstr_gty =
ProofEngineReduction.replace_lifting_csc 0