| Step | Hyp | Ref | Expression | 
						
							| 1 |  | coe1tm.z |  |-  .0. = ( 0g ` R ) | 
						
							| 2 |  | coe1tm.k |  |-  K = ( Base ` R ) | 
						
							| 3 |  | coe1tm.p |  |-  P = ( Poly1 ` R ) | 
						
							| 4 |  | coe1tm.x |  |-  X = ( var1 ` R ) | 
						
							| 5 |  | coe1tm.m |  |-  .x. = ( .s ` P ) | 
						
							| 6 |  | coe1tm.n |  |-  N = ( mulGrp ` P ) | 
						
							| 7 |  | coe1tm.e |  |-  .^ = ( .g ` N ) | 
						
							| 8 |  | coe1tmmul.b |  |-  B = ( Base ` P ) | 
						
							| 9 |  | coe1tmmul.t |  |-  .xb = ( .r ` P ) | 
						
							| 10 |  | coe1tmmul.u |  |-  .X. = ( .r ` R ) | 
						
							| 11 |  | coe1tmmul.a |  |-  ( ph -> A e. B ) | 
						
							| 12 |  | coe1tmmul.r |  |-  ( ph -> R e. Ring ) | 
						
							| 13 |  | coe1tmmul.c |  |-  ( ph -> C e. K ) | 
						
							| 14 |  | coe1tmmul.d |  |-  ( ph -> D e. NN0 ) | 
						
							| 15 |  | coe1tmmul2fv.y |  |-  ( ph -> Y e. NN0 ) | 
						
							| 16 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 | coe1tmmul2 |  |-  ( ph -> ( coe1 ` ( A .xb ( C .x. ( D .^ X ) ) ) ) = ( x e. NN0 |-> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) ) ) | 
						
							| 17 | 16 | fveq1d |  |-  ( ph -> ( ( coe1 ` ( A .xb ( C .x. ( D .^ X ) ) ) ) ` ( D + Y ) ) = ( ( x e. NN0 |-> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) ) ` ( D + Y ) ) ) | 
						
							| 18 | 14 15 | nn0addcld |  |-  ( ph -> ( D + Y ) e. NN0 ) | 
						
							| 19 |  | breq2 |  |-  ( x = ( D + Y ) -> ( D <_ x <-> D <_ ( D + Y ) ) ) | 
						
							| 20 |  | fvoveq1 |  |-  ( x = ( D + Y ) -> ( ( coe1 ` A ) ` ( x - D ) ) = ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) ) | 
						
							| 21 | 20 | oveq1d |  |-  ( x = ( D + Y ) -> ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) = ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) ) | 
						
							| 22 | 19 21 | ifbieq1d |  |-  ( x = ( D + Y ) -> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) = if ( D <_ ( D + Y ) , ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) , .0. ) ) | 
						
							| 23 |  | eqid |  |-  ( x e. NN0 |-> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) ) = ( x e. NN0 |-> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) ) | 
						
							| 24 |  | ovex |  |-  ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) e. _V | 
						
							| 25 | 1 | fvexi |  |-  .0. e. _V | 
						
							| 26 | 24 25 | ifex |  |-  if ( D <_ ( D + Y ) , ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) , .0. ) e. _V | 
						
							| 27 | 22 23 26 | fvmpt |  |-  ( ( D + Y ) e. NN0 -> ( ( x e. NN0 |-> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) ) ` ( D + Y ) ) = if ( D <_ ( D + Y ) , ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) , .0. ) ) | 
						
							| 28 | 18 27 | syl |  |-  ( ph -> ( ( x e. NN0 |-> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) ) ` ( D + Y ) ) = if ( D <_ ( D + Y ) , ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) , .0. ) ) | 
						
							| 29 | 14 | nn0red |  |-  ( ph -> D e. RR ) | 
						
							| 30 |  | nn0addge1 |  |-  ( ( D e. RR /\ Y e. NN0 ) -> D <_ ( D + Y ) ) | 
						
							| 31 | 29 15 30 | syl2anc |  |-  ( ph -> D <_ ( D + Y ) ) | 
						
							| 32 | 31 | iftrued |  |-  ( ph -> if ( D <_ ( D + Y ) , ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) , .0. ) = ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) ) | 
						
							| 33 | 14 | nn0cnd |  |-  ( ph -> D e. CC ) | 
						
							| 34 | 15 | nn0cnd |  |-  ( ph -> Y e. CC ) | 
						
							| 35 | 33 34 | pncan2d |  |-  ( ph -> ( ( D + Y ) - D ) = Y ) | 
						
							| 36 | 35 | fveq2d |  |-  ( ph -> ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) = ( ( coe1 ` A ) ` Y ) ) | 
						
							| 37 | 36 | oveq1d |  |-  ( ph -> ( ( ( coe1 ` A ) ` ( ( D + Y ) - D ) ) .X. C ) = ( ( ( coe1 ` A ) ` Y ) .X. C ) ) | 
						
							| 38 | 28 32 37 | 3eqtrd |  |-  ( ph -> ( ( x e. NN0 |-> if ( D <_ x , ( ( ( coe1 ` A ) ` ( x - D ) ) .X. C ) , .0. ) ) ` ( D + Y ) ) = ( ( ( coe1 ` A ) ` Y ) .X. C ) ) | 
						
							| 39 | 17 38 | eqtrd |  |-  ( ph -> ( ( coe1 ` ( A .xb ( C .x. ( D .^ X ) ) ) ) ` ( D + Y ) ) = ( ( ( coe1 ` A ) ` Y ) .X. C ) ) |