#!/usr/bin/env python
# coding: utf-8
import math

a = float('inf')
b = float('-inf')
c = float('nan')

a

b

c

math.isinf(a)

math.isnan(c)

a = float('inf')

a/a

b = float('-inf')

a + b

c = float('nan')

c + 23

c/2

math.sqrt(c)

c = float('nan')
d = float('nan')
c == d

c is d



