Metamath Proof Explorer


Theorem spanpr

Description: The span of a pair of vectors. (Contributed by NM, 9-Jun-2006) (New usage is discouraged.)

Ref Expression
Assertion spanpr A B span A + B span A B

Proof

Step Hyp Ref Expression
1 spansnsh A span A S
2 spansnsh B span B S
3 shscl span A S span B S span A + span B S
4 1 2 3 syl2an A B span A + span B S
5 4 adantr A B x span A + B span A + span B S
6 1 2 anim12i A B span A S span B S
7 spansnid A A span A
8 spansnid B B span B
9 7 8 anim12i A B A span A B span B
10 shsva span A S span B S A span A B span B A + B span A + span B
11 6 9 10 sylc A B A + B span A + span B
12 11 adantr A B x span A + B A + B span A + span B
13 simpr A B x span A + B x span A + B
14 elspansn3 span A + span B S A + B span A + span B x span A + B x span A + span B
15 5 12 13 14 syl3anc A B x span A + B x span A + span B
16 15 ex A B x span A + B x span A + span B
17 16 ssrdv A B span A + B span A + span B
18 df-pr A B = A B
19 18 fveq2i span A B = span A B
20 snssi A A
21 snssi B B
22 spanun A B span A B = span A + span B
23 20 21 22 syl2an A B span A B = span A + span B
24 19 23 eqtr2id A B span A + span B = span A B
25 17 24 sseqtrd A B span A + B span A B