> Why (briefly) is it not possible for Eq to work here? That's because inference system in assumptions module requires the boolean function as object, not type.
Known facts such as "x being real number implies x being complex number" is registered in assumptions/ask module as *Implies(Q.real, Q.complex)*. If we want to express "x > y implies both x and y being real number" with this system, we need something like* Implies(Q.gt, AllArgs(Q.real))* which is applied to Tuple(x, y). These boldface objects play the role of composite function, which requires boolean functions as objects. We cannot do Implies(Gt, AllArgs(Q.real)) because Gt is a type and thus cannot be the argument of Implies(). This is why we need Q.eq, Q.lt, and other predicates to represent Eq, Lt, etc in assumption system. Jisoo Song -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/cf455021-707c-4839-a5b6-41bb2a6b56d1n%40googlegroups.com.
