| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ccatmulgnn0dir.a |  |-  A = ( ( 0 ..^ M ) X. { K } ) | 
						
							| 2 |  | ccatmulgnn0dir.b |  |-  B = ( ( 0 ..^ N ) X. { K } ) | 
						
							| 3 |  | ccatmulgnn0dir.c |  |-  C = ( ( 0 ..^ ( M + N ) ) X. { K } ) | 
						
							| 4 |  | ccatmulgnn0dir.k |  |-  ( ph -> K e. S ) | 
						
							| 5 |  | ccatmulgnn0dir.m |  |-  ( ph -> M e. NN0 ) | 
						
							| 6 |  | ccatmulgnn0dir.n |  |-  ( ph -> N e. NN0 ) | 
						
							| 7 | 1 | fveq2i |  |-  ( # ` A ) = ( # ` ( ( 0 ..^ M ) X. { K } ) ) | 
						
							| 8 |  | fzofi |  |-  ( 0 ..^ M ) e. Fin | 
						
							| 9 |  | snfi |  |-  { K } e. Fin | 
						
							| 10 |  | hashxp |  |-  ( ( ( 0 ..^ M ) e. Fin /\ { K } e. Fin ) -> ( # ` ( ( 0 ..^ M ) X. { K } ) ) = ( ( # ` ( 0 ..^ M ) ) x. ( # ` { K } ) ) ) | 
						
							| 11 | 8 9 10 | mp2an |  |-  ( # ` ( ( 0 ..^ M ) X. { K } ) ) = ( ( # ` ( 0 ..^ M ) ) x. ( # ` { K } ) ) | 
						
							| 12 | 7 11 | eqtri |  |-  ( # ` A ) = ( ( # ` ( 0 ..^ M ) ) x. ( # ` { K } ) ) | 
						
							| 13 |  | hashfzo0 |  |-  ( M e. NN0 -> ( # ` ( 0 ..^ M ) ) = M ) | 
						
							| 14 | 5 13 | syl |  |-  ( ph -> ( # ` ( 0 ..^ M ) ) = M ) | 
						
							| 15 |  | hashsng |  |-  ( K e. S -> ( # ` { K } ) = 1 ) | 
						
							| 16 | 4 15 | syl |  |-  ( ph -> ( # ` { K } ) = 1 ) | 
						
							| 17 | 14 16 | oveq12d |  |-  ( ph -> ( ( # ` ( 0 ..^ M ) ) x. ( # ` { K } ) ) = ( M x. 1 ) ) | 
						
							| 18 | 12 17 | eqtrid |  |-  ( ph -> ( # ` A ) = ( M x. 1 ) ) | 
						
							| 19 | 5 | nn0cnd |  |-  ( ph -> M e. CC ) | 
						
							| 20 | 19 | mulridd |  |-  ( ph -> ( M x. 1 ) = M ) | 
						
							| 21 | 18 20 | eqtrd |  |-  ( ph -> ( # ` A ) = M ) | 
						
							| 22 | 2 | fveq2i |  |-  ( # ` B ) = ( # ` ( ( 0 ..^ N ) X. { K } ) ) | 
						
							| 23 |  | fzofi |  |-  ( 0 ..^ N ) e. Fin | 
						
							| 24 |  | hashxp |  |-  ( ( ( 0 ..^ N ) e. Fin /\ { K } e. Fin ) -> ( # ` ( ( 0 ..^ N ) X. { K } ) ) = ( ( # ` ( 0 ..^ N ) ) x. ( # ` { K } ) ) ) | 
						
							| 25 | 23 9 24 | mp2an |  |-  ( # ` ( ( 0 ..^ N ) X. { K } ) ) = ( ( # ` ( 0 ..^ N ) ) x. ( # ` { K } ) ) | 
						
							| 26 | 22 25 | eqtri |  |-  ( # ` B ) = ( ( # ` ( 0 ..^ N ) ) x. ( # ` { K } ) ) | 
						
							| 27 |  | hashfzo0 |  |-  ( N e. NN0 -> ( # ` ( 0 ..^ N ) ) = N ) | 
						
							| 28 | 6 27 | syl |  |-  ( ph -> ( # ` ( 0 ..^ N ) ) = N ) | 
						
							| 29 | 28 16 | oveq12d |  |-  ( ph -> ( ( # ` ( 0 ..^ N ) ) x. ( # ` { K } ) ) = ( N x. 1 ) ) | 
						
							| 30 | 26 29 | eqtrid |  |-  ( ph -> ( # ` B ) = ( N x. 1 ) ) | 
						
							| 31 | 6 | nn0cnd |  |-  ( ph -> N e. CC ) | 
						
							| 32 | 31 | mulridd |  |-  ( ph -> ( N x. 1 ) = N ) | 
						
							| 33 | 30 32 | eqtrd |  |-  ( ph -> ( # ` B ) = N ) | 
						
							| 34 | 21 33 | oveq12d |  |-  ( ph -> ( ( # ` A ) + ( # ` B ) ) = ( M + N ) ) | 
						
							| 35 | 34 | oveq2d |  |-  ( ph -> ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) = ( 0 ..^ ( M + N ) ) ) | 
						
							| 36 |  | simpll |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ i e. ( 0 ..^ ( # ` A ) ) ) -> ph ) | 
						
							| 37 |  | simpr |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ i e. ( 0 ..^ ( # ` A ) ) ) -> i e. ( 0 ..^ ( # ` A ) ) ) | 
						
							| 38 | 21 | oveq2d |  |-  ( ph -> ( 0 ..^ ( # ` A ) ) = ( 0 ..^ M ) ) | 
						
							| 39 | 36 38 | syl |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ i e. ( 0 ..^ ( # ` A ) ) ) -> ( 0 ..^ ( # ` A ) ) = ( 0 ..^ M ) ) | 
						
							| 40 | 37 39 | eleqtrd |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ i e. ( 0 ..^ ( # ` A ) ) ) -> i e. ( 0 ..^ M ) ) | 
						
							| 41 |  | fconstg |  |-  ( K e. S -> ( ( 0 ..^ M ) X. { K } ) : ( 0 ..^ M ) --> { K } ) | 
						
							| 42 | 4 41 | syl |  |-  ( ph -> ( ( 0 ..^ M ) X. { K } ) : ( 0 ..^ M ) --> { K } ) | 
						
							| 43 | 1 | a1i |  |-  ( ph -> A = ( ( 0 ..^ M ) X. { K } ) ) | 
						
							| 44 | 43 | feq1d |  |-  ( ph -> ( A : ( 0 ..^ M ) --> { K } <-> ( ( 0 ..^ M ) X. { K } ) : ( 0 ..^ M ) --> { K } ) ) | 
						
							| 45 | 42 44 | mpbird |  |-  ( ph -> A : ( 0 ..^ M ) --> { K } ) | 
						
							| 46 |  | fvconst |  |-  ( ( A : ( 0 ..^ M ) --> { K } /\ i e. ( 0 ..^ M ) ) -> ( A ` i ) = K ) | 
						
							| 47 | 45 46 | sylan |  |-  ( ( ph /\ i e. ( 0 ..^ M ) ) -> ( A ` i ) = K ) | 
						
							| 48 | 36 40 47 | syl2anc |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ i e. ( 0 ..^ ( # ` A ) ) ) -> ( A ` i ) = K ) | 
						
							| 49 |  | simpll |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ph ) | 
						
							| 50 |  | simplr |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) | 
						
							| 51 |  | simpr |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> -. i e. ( 0 ..^ ( # ` A ) ) ) | 
						
							| 52 | 21 5 | eqeltrd |  |-  ( ph -> ( # ` A ) e. NN0 ) | 
						
							| 53 | 49 52 | syl |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( # ` A ) e. NN0 ) | 
						
							| 54 | 53 | nn0zd |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( # ` A ) e. ZZ ) | 
						
							| 55 | 33 6 | eqeltrd |  |-  ( ph -> ( # ` B ) e. NN0 ) | 
						
							| 56 | 49 55 | syl |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( # ` B ) e. NN0 ) | 
						
							| 57 | 56 | nn0zd |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( # ` B ) e. ZZ ) | 
						
							| 58 |  | fzocatel |  |-  ( ( ( i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) /\ ( ( # ` A ) e. ZZ /\ ( # ` B ) e. ZZ ) ) -> ( i - ( # ` A ) ) e. ( 0 ..^ ( # ` B ) ) ) | 
						
							| 59 | 50 51 54 57 58 | syl22anc |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( i - ( # ` A ) ) e. ( 0 ..^ ( # ` B ) ) ) | 
						
							| 60 | 33 | oveq2d |  |-  ( ph -> ( 0 ..^ ( # ` B ) ) = ( 0 ..^ N ) ) | 
						
							| 61 | 49 60 | syl |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( 0 ..^ ( # ` B ) ) = ( 0 ..^ N ) ) | 
						
							| 62 | 59 61 | eleqtrd |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( i - ( # ` A ) ) e. ( 0 ..^ N ) ) | 
						
							| 63 |  | fconstg |  |-  ( K e. S -> ( ( 0 ..^ N ) X. { K } ) : ( 0 ..^ N ) --> { K } ) | 
						
							| 64 | 4 63 | syl |  |-  ( ph -> ( ( 0 ..^ N ) X. { K } ) : ( 0 ..^ N ) --> { K } ) | 
						
							| 65 | 2 | a1i |  |-  ( ph -> B = ( ( 0 ..^ N ) X. { K } ) ) | 
						
							| 66 | 65 | feq1d |  |-  ( ph -> ( B : ( 0 ..^ N ) --> { K } <-> ( ( 0 ..^ N ) X. { K } ) : ( 0 ..^ N ) --> { K } ) ) | 
						
							| 67 | 64 66 | mpbird |  |-  ( ph -> B : ( 0 ..^ N ) --> { K } ) | 
						
							| 68 |  | fvconst |  |-  ( ( B : ( 0 ..^ N ) --> { K } /\ ( i - ( # ` A ) ) e. ( 0 ..^ N ) ) -> ( B ` ( i - ( # ` A ) ) ) = K ) | 
						
							| 69 | 67 68 | sylan |  |-  ( ( ph /\ ( i - ( # ` A ) ) e. ( 0 ..^ N ) ) -> ( B ` ( i - ( # ` A ) ) ) = K ) | 
						
							| 70 | 49 62 69 | syl2anc |  |-  ( ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) /\ -. i e. ( 0 ..^ ( # ` A ) ) ) -> ( B ` ( i - ( # ` A ) ) ) = K ) | 
						
							| 71 | 48 70 | ifeqda |  |-  ( ( ph /\ i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) ) -> if ( i e. ( 0 ..^ ( # ` A ) ) , ( A ` i ) , ( B ` ( i - ( # ` A ) ) ) ) = K ) | 
						
							| 72 | 35 71 | mpteq12dva |  |-  ( ph -> ( i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) |-> if ( i e. ( 0 ..^ ( # ` A ) ) , ( A ` i ) , ( B ` ( i - ( # ` A ) ) ) ) ) = ( i e. ( 0 ..^ ( M + N ) ) |-> K ) ) | 
						
							| 73 |  | ovex |  |-  ( 0 ..^ M ) e. _V | 
						
							| 74 |  | snex |  |-  { K } e. _V | 
						
							| 75 | 73 74 | xpex |  |-  ( ( 0 ..^ M ) X. { K } ) e. _V | 
						
							| 76 | 1 75 | eqeltri |  |-  A e. _V | 
						
							| 77 |  | ovex |  |-  ( 0 ..^ N ) e. _V | 
						
							| 78 | 77 74 | xpex |  |-  ( ( 0 ..^ N ) X. { K } ) e. _V | 
						
							| 79 | 2 78 | eqeltri |  |-  B e. _V | 
						
							| 80 |  | ccatfval |  |-  ( ( A e. _V /\ B e. _V ) -> ( A ++ B ) = ( i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) |-> if ( i e. ( 0 ..^ ( # ` A ) ) , ( A ` i ) , ( B ` ( i - ( # ` A ) ) ) ) ) ) | 
						
							| 81 | 76 79 80 | mp2an |  |-  ( A ++ B ) = ( i e. ( 0 ..^ ( ( # ` A ) + ( # ` B ) ) ) |-> if ( i e. ( 0 ..^ ( # ` A ) ) , ( A ` i ) , ( B ` ( i - ( # ` A ) ) ) ) ) | 
						
							| 82 |  | fconstmpt |  |-  ( ( 0 ..^ ( M + N ) ) X. { K } ) = ( i e. ( 0 ..^ ( M + N ) ) |-> K ) | 
						
							| 83 | 3 82 | eqtri |  |-  C = ( i e. ( 0 ..^ ( M + N ) ) |-> K ) | 
						
							| 84 | 72 81 83 | 3eqtr4g |  |-  ( ph -> ( A ++ B ) = C ) |