// uses ai_placeholderToList
static S simplifyMatchJob1(MatchJob mj) {
  if (empty(mj.input) || empty(mj.struct)) ret "Solved";
  if (eqic(first(mj.input), first(mj.struct))) {
    matchJob_apply(f dropFirst, mj);
    ret "Simplified";
  }
  if (eqic(last(mj.input), last(mj.struct))) {
    matchJob_apply(f dropLast, mj);
    ret "Simplified";
  }
  
  // Full match with category
  if (l(mj.struct) == 1 && isAngleBracketed(first(mj.struct))) {
    S placeholder = deAngleBracket(first(mj.struct));
    S list = ai_placeholderToList().get(placeholder);
    if (list != null) {
      bool contained = mechList_containsTokens(list, mj.input);
      if (contained) {
        mj.vars.put(placeholder, joinWithSpace(mj.input));
        mj.clear();
        ret "Simplified";
      }
    }
  }
  
  // Match leading category with first word
  if (isAngleBracketed(first(mj.struct))) {
    S placeholder = deAngleBracket(first(mj.struct));
    S list = ai_placeholderToList().get(placeholder);
    if (list != null) {
      bool contained = mechList_containsTokens(list, ll(first(mj.input)));
      if (contained) {
        mj.vars.put(placeholder, first(mj.input));
        matchJob_apply(f dropFirst, mj);
        ret "Simplified";
      }
    }
  }
  
  ret "Nothing to do";
}