public Equals(String input, Map vars) {
LispReader lr = new LispReader(new StringReader(input));
String t = lr.next(); // read type
if (!t.equals("=")) {
System.err.println("= not found in Equals constructor");
System.exit(-1);
}
left = Exp.makeExp(lr.next(), vars);
right = Exp.makeExp(lr.next(), vars);
if (!wellTyped()) {
System.out.println("MISTYPED in Equals.java: " + this);
}
addToNameMap(Arrays.asList(left, right));
}