Induction proof concerning a sum of binomial coefficients: $\sum_{j=m}^n\binom{j}{m}=\binom{n+1}{m+1}$ I'm looking for a proof of this identity but where j=m not j=0
http://www.proofwiki.org/wiki/Sum_of_Binomial_Coefficients_over_Upper_Index
$$\sum_{j=m}^n\binom{j}{m}=\binom{n+1}{m+1}$$

Hint:  what is $\binom{2}{4}$?  what is $\binom{n-1}{n}?$
