| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ply1mpl0.m |  |-  M = ( 1o mPoly R ) | 
						
							| 2 |  | ply1mpl0.p |  |-  P = ( Poly1 ` R ) | 
						
							| 3 |  | ply1mpl0.z |  |-  .0. = ( 0g ` P ) | 
						
							| 4 |  | eqidd |  |-  ( T. -> ( Base ` P ) = ( Base ` P ) ) | 
						
							| 5 |  | eqid |  |-  ( Base ` P ) = ( Base ` P ) | 
						
							| 6 | 2 5 | ply1bas |  |-  ( Base ` P ) = ( Base ` ( 1o mPoly R ) ) | 
						
							| 7 | 1 | fveq2i |  |-  ( Base ` M ) = ( Base ` ( 1o mPoly R ) ) | 
						
							| 8 | 6 7 | eqtr4i |  |-  ( Base ` P ) = ( Base ` M ) | 
						
							| 9 | 8 | a1i |  |-  ( T. -> ( Base ` P ) = ( Base ` M ) ) | 
						
							| 10 |  | eqid |  |-  ( +g ` P ) = ( +g ` P ) | 
						
							| 11 | 2 1 10 | ply1plusg |  |-  ( +g ` P ) = ( +g ` M ) | 
						
							| 12 | 11 | a1i |  |-  ( T. -> ( +g ` P ) = ( +g ` M ) ) | 
						
							| 13 | 12 | oveqdr |  |-  ( ( T. /\ ( x e. ( Base ` P ) /\ y e. ( Base ` P ) ) ) -> ( x ( +g ` P ) y ) = ( x ( +g ` M ) y ) ) | 
						
							| 14 | 4 9 13 | grpidpropd |  |-  ( T. -> ( 0g ` P ) = ( 0g ` M ) ) | 
						
							| 15 | 14 | mptru |  |-  ( 0g ` P ) = ( 0g ` M ) | 
						
							| 16 | 3 15 | eqtri |  |-  .0. = ( 0g ` M ) |