A call hide c where c is a string that maps to one or more
constants, will prevent the quotation parser from parsing it as such;
it will just be parsed as a variable. (A string maps to a set of
possible constants because of the possibility of overloading.) The
function returns two lists. Both specify constants by way of pairs of
strings. The first list is of constants that the string might have
mapped to in parsing (specifically, in the absyn_to_term stage of
parsing), and the second is the list of constants that would have
tried to be printed as the string. It is important to note that the
two lists need not be the same.
The effect can be reversed by Parse.update_overload_maps. The
function reveal is only the inverse of hide if the only constants
mapped to by the string all have that string as their names. (These
constants will all be in different theories.)