Conversion to negate a rational literal of type :real.
DESCRIPTION
The call REAL_RAT_NEG_CONV `--c`, where c is a rational literal of type
:real, returns the theorem |- --c = d where d is the canonical rational
literal that is equal to c's negation. The literal c may be an integer
literal (&n or -- &n), a ratio (&p / &q or -- &p / &q), or a decimal
(#DDD.DDDD or #DDD.DDDDeNN). The returned value d is always put in the
form &p / &q or -- &p / &q with q > 1 and p and q sharing no common
factor, or simply &p or -- &p when that is impossible.
FAILURE CONDITIONS
Fails if applied to a term that is not the negation of one of the permitted
forms of rational literal of type :real.