!759

p {
  printStructure(snlToTree(""));
  printStructure(snlToTree(" // comment"));
  printStructure(snlToTree("i [= x]"));
  printStructure(snlToTree("X + 1"));
  printStructure(snlToTree("x + 1"));
  printStructure(snlToTree("1 + 1"));
  printStructure(snlToTree("for [x] and [y]"));
  printStructure(snlToTree("[in X]"));
  printStructure(snlToTree("[in S X]"));
}