Metamath Proof Explorer


Theorem spansneleq

Description: Membership relation that implies equality of spans. (Contributed by NM, 6-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion spansneleq BA0AspanBspanA=spanB

Proof

Step Hyp Ref Expression
1 elspansn BAspanBxA=xB
2 1 adantr BA0AspanBxA=xB
3 sneq A=xBA=xB
4 3 fveq2d A=xBspanA=spanxB
5 4 ad2antll BA0xA=xBspanA=spanxB
6 oveq1 x=0xB=0B
7 ax-hvmul0 B0B=0
8 6 7 sylan9eqr Bx=0xB=0
9 8 ex Bx=0xB=0
10 eqeq1 A=xBA=0xB=0
11 10 biimprd A=xBxB=0A=0
12 9 11 sylan9 BA=xBx=0A=0
13 12 necon3d BA=xBA0x0
14 13 ex BA=xBA0x0
15 14 com23 BA0A=xBx0
16 15 impd BA0A=xBx0
17 16 adantr BxA0A=xBx0
18 spansncol Bxx0spanxB=spanB
19 18 3expia Bxx0spanxB=spanB
20 17 19 syld BxA0A=xBspanxB=spanB
21 20 exp4b BxA0A=xBspanxB=spanB
22 21 com23 BA0xA=xBspanxB=spanB
23 22 imp43 BA0xA=xBspanxB=spanB
24 5 23 eqtrd BA0xA=xBspanA=spanB
25 24 rexlimdvaa BA0xA=xBspanA=spanB
26 2 25 sylbid BA0AspanBspanA=spanB