   s3 = unify (subExp s2, opTea), [arg.tea, returnName]
   [(concatMaps s3, s2, s1), nextIndex, (subExp s3, returnName)]
 
-
-
-unify = (t1, t2) ->
-  unifyWith newMap(), [[t1, t2]]
-
 unifyWith = (subs, pairs) ->
   if pairs.length is 0
     subs

    cb ast
  ast

inside = (node) -> node[1...-1]

matchNode = (to, node) ->

    ['brace', token in ['{', '}']]
    ['whitespace', /^\s+$/.test token]

_isCollectionDelim = (atom) ->
  atom.label in ['bracket', 'brace']

typed = (a, b) ->
  b.type = a.type
  b
