#3 Existential and universal quantifications don't parse

[Robert P. Goldman]

I find that I am unable to get even the simplest forall or exists operations to parse successfully. E.g.:

iben>  vars x y z
iben> expr := z = x ^ y
iben> print expr
<0:0, 1:0, 2:0><0:0, 1:1, 2:1><0:1, 1:0, 2:1><0:1, 1:1, 2:0>
iben> exists x & y (expr & z)
Error: parse error
iben> exists x & y ((expr & z))
Error: parse error
iben> exists x & y (expr)
Error: parse error
iben> exists (x & y) expr
Error: parse error
iben> exists x (expr)
Error: parse error
iben> exists x ( expr )
Error: parse error
iben> forall x ( expr )
Error: parse error

These all seem to agree with the documentation and with grammar.yy to the limited extent that I understand the latter.