Metamath Proof Explorer


Theorem spansncv2

Description: Hilbert space has the covering property (using spans of singletons to represent atoms). Proposition 1(ii) of Kalmbach p. 153. (Contributed by NM, 9-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion spansncv2 A C B ¬ span B A A A span B

Proof

Step Hyp Ref Expression
1 spansncv A C x C B A x x A span B x = A span B
2 1 3exp A C x C B A x x A span B x = A span B
3 2 com23 A C B x C A x x A span B x = A span B
4 3 imp A C B x C A x x A span B x = A span B
5 4 ralrimiv A C B x C A x x A span B x = A span B
6 5 anim2i A A span B A C B A A span B x C A x x A span B x = A span B
7 6 expcom A C B A A span B A A span B x C A x x A span B x = A span B
8 spansnch B span B C
9 chnle A C span B C ¬ span B A A A span B
10 8 9 sylan2 A C B ¬ span B A A A span B
11 chjcl A C span B C A span B C
12 8 11 sylan2 A C B A span B C
13 cvbr2 A C A span B C A A span B A A span B x C A x x A span B x = A span B
14 12 13 syldan A C B A A span B A A span B x C A x x A span B x = A span B
15 7 10 14 3imtr4d A C B ¬ span B A A A span B