Proof of direct sum with span and basis
62077
Prove that if $W_1\subseteq V$ finite-dimensional, then there is $W_2\subseteq V$ such that $V=W_1\oplus W_2$
133076
Prove this sum equal to an expression.
13723
Doubly stochastic matrix proof
85222
Direct sum of finitely-many non-abelian groups
88728
Dimensions of vector subspaces in a direct sum are additive
10875
proof of binomial identity involving double sum
143540
How to prove this decomposition of sum of squares?
143113
Non-inductive, not combinatorial proof of $\sum_{i \mathop = 0}^n \binom n i^2 = \binom {2 n} n$
26790
Proving the geometric sum formula by induction
3543
Prove set is basis for $R^3$
29692
Proof verification: elementary Number Theory Proof of $am+bn = 1$
141762
The direct sum of two closed subspace is closed? (Hilbert space)
50114
A question about direct sums and products of modules
6366
Combinatorial proof of summation of $\sum\limits_{k = 0}^n {n \choose k}^2= {2n \choose n}$
15164
Proof of $\sum^{2N}_{n=1} \frac{(-1)^{n-1}}{n} = \sum^{N}_{n=1} \frac{1}{N+n}$
114277
Proving in Discrete Structures Problem that $2^N = \binom{N}{0} + \binom{N}{1} + \binom{N}{2} + \dots + \binom{N}{N}$
33104
Combinatorial Proof with Summation Identity