Thibaut Dumont

 12 Show $(W_1 + W_2 )^\perp = W_1^\perp \cap W_2^\perp$ and $W_1^\perp + W_2^\perp ⊆ (W_1 \cap W_2 )^\perp$ 5 How do I write this proof formally? 4 How come Cantor set is 'the' Cantor Set? 3 Action of the fundamental group 2 Infinite dimensional spaces and norm equivalence

### Reputation (615)

 +60 Show $(W_1 + W_2 )^\perp = W_1^\perp \cap W_2^\perp$ and $W_1^\perp + W_2^\perp ⊆ (W_1 \cap W_2 )^\perp$ +25 Correctly defining an application in a set of permutations +2 Same order groups +2 How to find area of triangle from its medians

### Question (1)

 2 Example of non-reversible folding of a thin chamber complex.

### Tags (19)

 12 inner-product-space 3 manifolds 5 proof-writing 2 normed-spaces 4 linear-algebra × 3 2 ordinary-differential-equations 4 general-topology 2 elementary-set-theory 3 homotopy-theory 2 functional-analysis

### Bookmarks (22)

 1052 Is $\frac{\textrm{d}y}{\textrm{d}x}$ not a ratio? 176 Can we ascertain that there exists an epimorphism $G\rightarrow H$? 164 How to define a bijection between $(0,1)$ and $(0,1]$? 44 Given a group $G$, how many topological/Lie group structures does $G$ have? 43 What is $\tau(A_n)$?

### Accounts (11)

 Mathematics 615 rep 44 silver badges1515 bronze badges MathOverflow 183 rep 88 bronze badges TeX - LaTeX 101 rep 33 bronze badges Academia 101 rep 22 bronze badges Anime & Manga 101 rep 22 bronze badges