Let K < K be two strike prices, each associated with a different call. These two calls are European calls, both on the same underlying non dividend paying stock and for the same expiration date, T. Denote the premium of the call associated with K by C, and the premium of the call associated with K,by C. Prove: The difference between the premiums of the two calls, C-C cannot exceed (must be less than or equal to) the discounted value of the difference between the strike prices, PV[K - K] In notations, (numbers are not accepted) prove that: C-C (K-K)e(T-t)