Metamath Proof Explorer


Theorem fsum2cn

Description: Version of fsumcn for two-argument mappings. (Contributed by Mario Carneiro, 6-May-2014)

Ref Expression
Hypotheses fsumcn.3 K=TopOpenfld
fsumcn.4 φJTopOnX
fsumcn.5 φAFin
fsum2cn.7 φLTopOnY
fsum2cn.8 φkAxX,yYBJ×tLCnK
Assertion fsum2cn φxX,yYkABJ×tLCnK

Proof

Step Hyp Ref Expression
1 fsumcn.3 K=TopOpenfld
2 fsumcn.4 φJTopOnX
3 fsumcn.5 φAFin
4 fsum2cn.7 φLTopOnY
5 fsum2cn.8 φkAxX,yYBJ×tLCnK
6 nfcv _ukAB
7 nfcv _vkAB
8 nfcv _xA
9 nfcv _xv
10 nfcsb1v _xu/xB
11 9 10 nfcsbw _xv/yu/xB
12 8 11 nfsum _xkAv/yu/xB
13 nfcv _yA
14 nfcsb1v _yv/yu/xB
15 13 14 nfsum _ykAv/yu/xB
16 csbeq1a x=uB=u/xB
17 csbeq1a y=vu/xB=v/yu/xB
18 16 17 sylan9eq x=uy=vB=v/yu/xB
19 18 sumeq2sdv x=uy=vkAB=kAv/yu/xB
20 6 7 12 15 19 cbvmpo xX,yYkAB=uX,vYkAv/yu/xB
21 vex uV
22 vex vV
23 21 22 op2ndd z=uv2ndz=v
24 23 csbeq1d z=uv2ndz/y1stz/xB=v/y1stz/xB
25 21 22 op1std z=uv1stz=u
26 25 csbeq1d z=uv1stz/xB=u/xB
27 26 csbeq2dv z=uvv/y1stz/xB=v/yu/xB
28 24 27 eqtrd z=uv2ndz/y1stz/xB=v/yu/xB
29 28 sumeq2sdv z=uvkA2ndz/y1stz/xB=kAv/yu/xB
30 29 mpompt zX×YkA2ndz/y1stz/xB=uX,vYkAv/yu/xB
31 20 30 eqtr4i xX,yYkAB=zX×YkA2ndz/y1stz/xB
32 txtopon JTopOnXLTopOnYJ×tLTopOnX×Y
33 2 4 32 syl2anc φJ×tLTopOnX×Y
34 nfcv _uB
35 nfcv _vB
36 34 35 11 14 18 cbvmpo xX,yYB=uX,vYv/yu/xB
37 28 mpompt zX×Y2ndz/y1stz/xB=uX,vYv/yu/xB
38 36 37 eqtr4i xX,yYB=zX×Y2ndz/y1stz/xB
39 38 5 eqeltrrid φkAzX×Y2ndz/y1stz/xBJ×tLCnK
40 1 33 3 39 fsumcn φzX×YkA2ndz/y1stz/xBJ×tLCnK
41 31 40 eqeltrid φxX,yYkABJ×tLCnK