Logtk.JP_unifSourceval iterate :
?flex_same:bool ->
scope:Scoped.scope ->
counter:int ref ->
T.t ->
T.t ->
(T.var * 'a) CCList.t ->
Unif_subst.t option OSeq.tFind disagreeing subterms. This function also returns a list of variables occurring above the disagreement pair, along with the index of the argument that the disagreement pair occurs in.