Function Z3_get_decl_rational_parameter 

pub unsafe extern "C" fn Z3_get_decl_rational_parameter(
    c: Z3_context,
    d: Z3_func_decl,
    idx: c_uint,
) -> Z3_string

Return the rational value, as a string, associated with a rational parameter.

Preconditions:

• Z3_get_decl_parameter_kind(c, d, idx) == ParameterKind::Rational