I have a nested sum like so:
k∗∑k1=k0 ...k∗∑kn=kn−1⏟n times1 with n,k0,k∗∈N, k∗≥k0
Is there a general, shorter representation that spares me calculating the actual sums?
Answer
∑k0≤k1≤⋯≤kn≤k∗1=∑1≤k1−k0+1<k2−k0+2<⋯<kn−k0+n≤k∗−k0+n1=(k∗−k0+nn)
I have injection f:A→B and I want to get bijection. Can I just resting codomain to f(A)? I know that every function i...
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