| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elznn0 |  |-  ( C e. ZZ <-> ( C e. RR /\ ( C e. NN0 \/ -u C e. NN0 ) ) ) | 
						
							| 2 |  | cxpmul2 |  |-  ( ( A e. CC /\ B e. CC /\ C e. NN0 ) -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) | 
						
							| 3 | 2 | 3expia |  |-  ( ( A e. CC /\ B e. CC ) -> ( C e. NN0 -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) ) | 
						
							| 4 | 3 | ad4ant13 |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ C e. RR ) -> ( C e. NN0 -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) ) | 
						
							| 5 |  | simplll |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> A e. CC ) | 
						
							| 6 |  | simplr |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> B e. CC ) | 
						
							| 7 |  | simprr |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> -u C e. NN0 ) | 
						
							| 8 |  | cxpmul2 |  |-  ( ( A e. CC /\ B e. CC /\ -u C e. NN0 ) -> ( A ^c ( B x. -u C ) ) = ( ( A ^c B ) ^ -u C ) ) | 
						
							| 9 | 5 6 7 8 | syl3anc |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( A ^c ( B x. -u C ) ) = ( ( A ^c B ) ^ -u C ) ) | 
						
							| 10 | 9 | oveq2d |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( 1 / ( A ^c ( B x. -u C ) ) ) = ( 1 / ( ( A ^c B ) ^ -u C ) ) ) | 
						
							| 11 |  | simprl |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> C e. RR ) | 
						
							| 12 | 11 | recnd |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> C e. CC ) | 
						
							| 13 | 6 12 | mulneg2d |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( B x. -u C ) = -u ( B x. C ) ) | 
						
							| 14 | 13 | negeqd |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> -u ( B x. -u C ) = -u -u ( B x. C ) ) | 
						
							| 15 | 6 12 | mulcld |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( B x. C ) e. CC ) | 
						
							| 16 | 15 | negnegd |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> -u -u ( B x. C ) = ( B x. C ) ) | 
						
							| 17 | 14 16 | eqtrd |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> -u ( B x. -u C ) = ( B x. C ) ) | 
						
							| 18 | 17 | oveq2d |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( A ^c -u ( B x. -u C ) ) = ( A ^c ( B x. C ) ) ) | 
						
							| 19 |  | simpllr |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> A =/= 0 ) | 
						
							| 20 | 12 | negcld |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> -u C e. CC ) | 
						
							| 21 | 6 20 | mulcld |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( B x. -u C ) e. CC ) | 
						
							| 22 |  | cxpneg |  |-  ( ( A e. CC /\ A =/= 0 /\ ( B x. -u C ) e. CC ) -> ( A ^c -u ( B x. -u C ) ) = ( 1 / ( A ^c ( B x. -u C ) ) ) ) | 
						
							| 23 | 5 19 21 22 | syl3anc |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( A ^c -u ( B x. -u C ) ) = ( 1 / ( A ^c ( B x. -u C ) ) ) ) | 
						
							| 24 | 18 23 | eqtr3d |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( A ^c ( B x. C ) ) = ( 1 / ( A ^c ( B x. -u C ) ) ) ) | 
						
							| 25 |  | cxpcl |  |-  ( ( A e. CC /\ B e. CC ) -> ( A ^c B ) e. CC ) | 
						
							| 26 | 25 | ad4ant13 |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( A ^c B ) e. CC ) | 
						
							| 27 |  | expneg2 |  |-  ( ( ( A ^c B ) e. CC /\ C e. CC /\ -u C e. NN0 ) -> ( ( A ^c B ) ^ C ) = ( 1 / ( ( A ^c B ) ^ -u C ) ) ) | 
						
							| 28 | 26 12 7 27 | syl3anc |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( ( A ^c B ) ^ C ) = ( 1 / ( ( A ^c B ) ^ -u C ) ) ) | 
						
							| 29 | 10 24 28 | 3eqtr4d |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ ( C e. RR /\ -u C e. NN0 ) ) -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) | 
						
							| 30 | 29 | expr |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ C e. RR ) -> ( -u C e. NN0 -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) ) | 
						
							| 31 | 4 30 | jaod |  |-  ( ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) /\ C e. RR ) -> ( ( C e. NN0 \/ -u C e. NN0 ) -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) ) | 
						
							| 32 | 31 | expimpd |  |-  ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) -> ( ( C e. RR /\ ( C e. NN0 \/ -u C e. NN0 ) ) -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) ) | 
						
							| 33 | 1 32 | biimtrid |  |-  ( ( ( A e. CC /\ A =/= 0 ) /\ B e. CC ) -> ( C e. ZZ -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) ) | 
						
							| 34 | 33 | impr |  |-  ( ( ( A e. CC /\ A =/= 0 ) /\ ( B e. CC /\ C e. ZZ ) ) -> ( A ^c ( B x. C ) ) = ( ( A ^c B ) ^ C ) ) |