!7

srecord ProposeRewrite(S a, S b) {}

p-exp {
  new ThoughtSpace1 ts;
  ts.setInput("let's have a cup of Joe");
  ts.add(Definition("let's have", "a grouping prefix"));
  ts.addStepper(voidfunc(ThoughtSpace1 ts) {
    S s = ts.getInput();
    if (empty(s)) ret;
    for (S prefix : sentencePrefixes_notEmpty_rev(s))
      if (cic(ts.getDefinitionTexts(prefix),
        "a grouping prefix"))
      ts.add(ProposeRewrite(s, prefix + " " + curlyBrace(trim(dropPrefix(prefix, s)))));
  });
  ts.printStats = true;
  ts.think(true);
}