Metamath Proof Explorer


Theorem marepvval

Description: Third substitution for the definition of the function replacing a column of a matrix by a vector. (Contributed by AV, 14-Feb-2019) (Revised by AV, 26-Feb-2019)

Ref Expression
Hypotheses marepvfval.a A = N Mat R
marepvfval.b B = Base A
marepvfval.q Q = N matRepV R
marepvfval.v V = Base R N
Assertion marepvval M B C V K N M Q C K = i N , j N if j = K C i i M j

Proof

Step Hyp Ref Expression
1 marepvfval.a A = N Mat R
2 marepvfval.b B = Base A
3 marepvfval.q Q = N matRepV R
4 marepvfval.v V = Base R N
5 1 2 3 4 marepvval0 M B C V M Q C = k N i N , j N if j = k C i i M j
6 5 3adant3 M B C V K N M Q C = k N i N , j N if j = k C i i M j
7 6 fveq1d M B C V K N M Q C K = k N i N , j N if j = k C i i M j K
8 eqid k N i N , j N if j = k C i i M j = k N i N , j N if j = k C i i M j
9 eqeq2 k = K j = k j = K
10 9 ifbid k = K if j = k C i i M j = if j = K C i i M j
11 10 mpoeq3dv k = K i N , j N if j = k C i i M j = i N , j N if j = K C i i M j
12 simp3 M B C V K N K N
13 1 2 matrcl M B N Fin R V
14 13 simpld M B N Fin
15 14 14 jca M B N Fin N Fin
16 15 3ad2ant1 M B C V K N N Fin N Fin
17 mpoexga N Fin N Fin i N , j N if j = K C i i M j V
18 16 17 syl M B C V K N i N , j N if j = K C i i M j V
19 8 11 12 18 fvmptd3 M B C V K N k N i N , j N if j = k C i i M j K = i N , j N if j = K C i i M j
20 7 19 eqtrd M B C V K N M Q C K = i N , j N if j = K C i i M j