| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cayleylem1.x | ⊢ 𝑋  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | cayleylem1.p | ⊢  +   =  ( +g ‘ 𝐺 ) | 
						
							| 3 |  | cayleylem1.u | ⊢  0   =  ( 0g ‘ 𝐺 ) | 
						
							| 4 |  | cayleylem1.h | ⊢ 𝐻  =  ( SymGrp ‘ 𝑋 ) | 
						
							| 5 |  | cayleylem1.s | ⊢ 𝑆  =  ( Base ‘ 𝐻 ) | 
						
							| 6 |  | cayleylem1.f | ⊢ 𝐹  =  ( 𝑔  ∈  𝑋  ↦  ( 𝑎  ∈  𝑋  ↦  ( 𝑔  +  𝑎 ) ) ) | 
						
							| 7 |  | eqid | ⊢ ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) )  =  ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) ) | 
						
							| 8 | 1 2 7 | gaid2 | ⊢ ( 𝐺  ∈  Grp  →  ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) )  ∈  ( 𝐺  GrpAct  𝑋 ) ) | 
						
							| 9 |  | oveq12 | ⊢ ( ( 𝑥  =  𝑔  ∧  𝑦  =  𝑎 )  →  ( 𝑥  +  𝑦 )  =  ( 𝑔  +  𝑎 ) ) | 
						
							| 10 |  | ovex | ⊢ ( 𝑔  +  𝑎 )  ∈  V | 
						
							| 11 | 9 7 10 | ovmpoa | ⊢ ( ( 𝑔  ∈  𝑋  ∧  𝑎  ∈  𝑋 )  →  ( 𝑔 ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) ) 𝑎 )  =  ( 𝑔  +  𝑎 ) ) | 
						
							| 12 | 11 | mpteq2dva | ⊢ ( 𝑔  ∈  𝑋  →  ( 𝑎  ∈  𝑋  ↦  ( 𝑔 ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) ) 𝑎 ) )  =  ( 𝑎  ∈  𝑋  ↦  ( 𝑔  +  𝑎 ) ) ) | 
						
							| 13 | 12 | mpteq2ia | ⊢ ( 𝑔  ∈  𝑋  ↦  ( 𝑎  ∈  𝑋  ↦  ( 𝑔 ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) ) 𝑎 ) ) )  =  ( 𝑔  ∈  𝑋  ↦  ( 𝑎  ∈  𝑋  ↦  ( 𝑔  +  𝑎 ) ) ) | 
						
							| 14 | 6 13 | eqtr4i | ⊢ 𝐹  =  ( 𝑔  ∈  𝑋  ↦  ( 𝑎  ∈  𝑋  ↦  ( 𝑔 ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) ) 𝑎 ) ) ) | 
						
							| 15 | 1 4 14 | galactghm | ⊢ ( ( 𝑥  ∈  𝑋 ,  𝑦  ∈  𝑋  ↦  ( 𝑥  +  𝑦 ) )  ∈  ( 𝐺  GrpAct  𝑋 )  →  𝐹  ∈  ( 𝐺  GrpHom  𝐻 ) ) | 
						
							| 16 | 8 15 | syl | ⊢ ( 𝐺  ∈  Grp  →  𝐹  ∈  ( 𝐺  GrpHom  𝐻 ) ) |