| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pwsmgp.y | ⊢ 𝑌  =  ( 𝑅  ↑s  𝐼 ) | 
						
							| 2 |  | pwsmgp.m | ⊢ 𝑀  =  ( mulGrp ‘ 𝑅 ) | 
						
							| 3 |  | pwsmgp.z | ⊢ 𝑍  =  ( 𝑀  ↑s  𝐼 ) | 
						
							| 4 |  | pwsmgp.n | ⊢ 𝑁  =  ( mulGrp ‘ 𝑌 ) | 
						
							| 5 |  | pwsmgp.b | ⊢ 𝐵  =  ( Base ‘ 𝑁 ) | 
						
							| 6 |  | pwsmgp.c | ⊢ 𝐶  =  ( Base ‘ 𝑍 ) | 
						
							| 7 |  | pwsmgp.p | ⊢  +   =  ( +g ‘ 𝑁 ) | 
						
							| 8 |  | pwsmgp.q | ⊢  ✚   =  ( +g ‘ 𝑍 ) | 
						
							| 9 |  | eqid | ⊢ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) )  =  ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) | 
						
							| 10 |  | eqid | ⊢ ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) )  =  ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) | 
						
							| 11 |  | eqid | ⊢ ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) )  =  ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) | 
						
							| 12 |  | simpr | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  𝐼  ∈  𝑊 ) | 
						
							| 13 |  | fvexd | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( Scalar ‘ 𝑅 )  ∈  V ) | 
						
							| 14 |  | fnconstg | ⊢ ( 𝑅  ∈  𝑉  →  ( 𝐼  ×  { 𝑅 } )  Fn  𝐼 ) | 
						
							| 15 | 14 | adantr | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( 𝐼  ×  { 𝑅 } )  Fn  𝐼 ) | 
						
							| 16 | 9 10 11 12 13 15 | prdsmgp | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( ( Base ‘ ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) )  =  ( Base ‘ ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) )  ∧  ( +g ‘ ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) )  =  ( +g ‘ ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) ) ) | 
						
							| 17 | 16 | simpld | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( Base ‘ ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) )  =  ( Base ‘ ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) ) | 
						
							| 18 |  | eqid | ⊢ ( Scalar ‘ 𝑅 )  =  ( Scalar ‘ 𝑅 ) | 
						
							| 19 | 1 18 | pwsval | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  𝑌  =  ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) | 
						
							| 20 | 19 | fveq2d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( mulGrp ‘ 𝑌 )  =  ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) ) | 
						
							| 21 | 4 20 | eqtrid | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  𝑁  =  ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) ) | 
						
							| 22 | 21 | fveq2d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( Base ‘ 𝑁 )  =  ( Base ‘ ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) ) ) | 
						
							| 23 | 2 | fvexi | ⊢ 𝑀  ∈  V | 
						
							| 24 |  | eqid | ⊢ ( 𝑀  ↑s  𝐼 )  =  ( 𝑀  ↑s  𝐼 ) | 
						
							| 25 |  | eqid | ⊢ ( Scalar ‘ 𝑀 )  =  ( Scalar ‘ 𝑀 ) | 
						
							| 26 | 24 25 | pwsval | ⊢ ( ( 𝑀  ∈  V  ∧  𝐼  ∈  𝑊 )  →  ( 𝑀  ↑s  𝐼 )  =  ( ( Scalar ‘ 𝑀 ) Xs ( 𝐼  ×  { 𝑀 } ) ) ) | 
						
							| 27 | 23 12 26 | sylancr | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( 𝑀  ↑s  𝐼 )  =  ( ( Scalar ‘ 𝑀 ) Xs ( 𝐼  ×  { 𝑀 } ) ) ) | 
						
							| 28 | 2 18 | mgpsca | ⊢ ( Scalar ‘ 𝑅 )  =  ( Scalar ‘ 𝑀 ) | 
						
							| 29 | 28 | eqcomi | ⊢ ( Scalar ‘ 𝑀 )  =  ( Scalar ‘ 𝑅 ) | 
						
							| 30 | 29 | a1i | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( Scalar ‘ 𝑀 )  =  ( Scalar ‘ 𝑅 ) ) | 
						
							| 31 | 2 | sneqi | ⊢ { 𝑀 }  =  { ( mulGrp ‘ 𝑅 ) } | 
						
							| 32 | 31 | xpeq2i | ⊢ ( 𝐼  ×  { 𝑀 } )  =  ( 𝐼  ×  { ( mulGrp ‘ 𝑅 ) } ) | 
						
							| 33 |  | fnmgp | ⊢ mulGrp  Fn  V | 
						
							| 34 |  | elex | ⊢ ( 𝑅  ∈  𝑉  →  𝑅  ∈  V ) | 
						
							| 35 | 34 | adantr | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  𝑅  ∈  V ) | 
						
							| 36 |  | fcoconst | ⊢ ( ( mulGrp  Fn  V  ∧  𝑅  ∈  V )  →  ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) )  =  ( 𝐼  ×  { ( mulGrp ‘ 𝑅 ) } ) ) | 
						
							| 37 | 33 35 36 | sylancr | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) )  =  ( 𝐼  ×  { ( mulGrp ‘ 𝑅 ) } ) ) | 
						
							| 38 | 32 37 | eqtr4id | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( 𝐼  ×  { 𝑀 } )  =  ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) | 
						
							| 39 | 30 38 | oveq12d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( ( Scalar ‘ 𝑀 ) Xs ( 𝐼  ×  { 𝑀 } ) )  =  ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) | 
						
							| 40 | 27 39 | eqtrd | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( 𝑀  ↑s  𝐼 )  =  ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) | 
						
							| 41 | 3 40 | eqtrid | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  𝑍  =  ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) | 
						
							| 42 | 41 | fveq2d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( Base ‘ 𝑍 )  =  ( Base ‘ ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) ) | 
						
							| 43 | 17 22 42 | 3eqtr4d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( Base ‘ 𝑁 )  =  ( Base ‘ 𝑍 ) ) | 
						
							| 44 | 43 5 6 | 3eqtr4g | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  𝐵  =  𝐶 ) | 
						
							| 45 | 16 | simprd | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( +g ‘ ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) )  =  ( +g ‘ ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) ) | 
						
							| 46 | 21 | fveq2d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( +g ‘ 𝑁 )  =  ( +g ‘ ( mulGrp ‘ ( ( Scalar ‘ 𝑅 ) Xs ( 𝐼  ×  { 𝑅 } ) ) ) ) ) | 
						
							| 47 | 41 | fveq2d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( +g ‘ 𝑍 )  =  ( +g ‘ ( ( Scalar ‘ 𝑅 ) Xs ( mulGrp  ∘  ( 𝐼  ×  { 𝑅 } ) ) ) ) ) | 
						
							| 48 | 45 46 47 | 3eqtr4d | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( +g ‘ 𝑁 )  =  ( +g ‘ 𝑍 ) ) | 
						
							| 49 | 48 7 8 | 3eqtr4g | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →   +   =   ✚  ) | 
						
							| 50 | 44 49 | jca | ⊢ ( ( 𝑅  ∈  𝑉  ∧  𝐼  ∈  𝑊 )  →  ( 𝐵  =  𝐶  ∧   +   =   ✚  ) ) |