apply_hom_vars :: [SORT] -> [CASLTERM] -> [CASLTERM]
apply_hom_vars (s : ss) (t : ts) = t' : ts'
      where ot_hom = Op_type Partial [mkFreeName s] s nullRange
            name_hom = mkQualOp homId ot_hom
            t' = mkAppl name_hom [t]
            ts' = apply_hom_vars ss ts
apply_hom_vars :: [SORT] -> [CASLTERM] -> [CASLTERM]
apply_hom_vars (s : ss) (t : ts) = t' : ts'
      where ot_hom = Op_type Partial [mkFreeName s] s nullRange
            name_hom = mkQualOp homId ot_hom
            t' = mkAppl name_hom [t]
            ts' = apply_hom_vars ss ts
apply_hom_vars (s : ss) (t : ts) = t' : ts'
      where ot_hom = Op_type Partial [mkFreeName s] s nullRange
            name_hom = mkQualOp homId ot_hom
            t' = mkAppl name_hom [t]
            ts' = apply_hom_vars ss ts