-==================== Typechecked ====================
-Twist2{-r4,x-}{i} = \ tpl_B1 -> Twist2{-r4,x-}{i} {tpl_B1}
-Twine2{-r8,x-}{i} = \ tpl_B1 -> Twine2{-r8,x-}{i} {tpl_B1}
-AbsBinds [] [] [([], $d1{-rBi,x-}, d.Eval_aBa)]
- d.Eval_aBa = ({-dict-} [] [])
-AbsBinds [] [] [([], $d2{-rBk,x-}, d.Eval_aBf)]
- d.Eval_aBf = ({-dict-} [] [])
-