| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ply1plusg.y |  |-  Y = ( Poly1 ` R ) | 
						
							| 2 |  | ply1plusg.s |  |-  S = ( 1o mPoly R ) | 
						
							| 3 |  | ply1vscafval.n |  |-  .x. = ( .s ` Y ) | 
						
							| 4 |  | eqid |  |-  ( 1o mPwSer R ) = ( 1o mPwSer R ) | 
						
							| 5 |  | eqid |  |-  ( .s ` S ) = ( .s ` S ) | 
						
							| 6 | 2 4 5 | mplvsca2 |  |-  ( .s ` S ) = ( .s ` ( 1o mPwSer R ) ) | 
						
							| 7 |  | eqid |  |-  ( PwSer1 ` R ) = ( PwSer1 ` R ) | 
						
							| 8 |  | eqid |  |-  ( .s ` ( PwSer1 ` R ) ) = ( .s ` ( PwSer1 ` R ) ) | 
						
							| 9 | 7 4 8 | psr1vsca |  |-  ( .s ` ( PwSer1 ` R ) ) = ( .s ` ( 1o mPwSer R ) ) | 
						
							| 10 |  | fvex |  |-  ( Base ` ( 1o mPoly R ) ) e. _V | 
						
							| 11 | 1 7 | ply1val |  |-  Y = ( ( PwSer1 ` R ) |`s ( Base ` ( 1o mPoly R ) ) ) | 
						
							| 12 | 11 8 | ressvsca |  |-  ( ( Base ` ( 1o mPoly R ) ) e. _V -> ( .s ` ( PwSer1 ` R ) ) = ( .s ` Y ) ) | 
						
							| 13 | 10 12 | ax-mp |  |-  ( .s ` ( PwSer1 ` R ) ) = ( .s ` Y ) | 
						
							| 14 | 6 9 13 | 3eqtr2i |  |-  ( .s ` S ) = ( .s ` Y ) | 
						
							| 15 | 3 14 | eqtr4i |  |-  .x. = ( .s ` S ) |