| Step | Hyp | Ref | Expression | 
						
							| 1 |  | gimghm | ⊢ ( 𝐹  ∈  ( 𝑀  GrpIso  𝑁 )  →  𝐹  ∈  ( 𝑀  GrpHom  𝑁 ) ) | 
						
							| 2 |  | ghmgrp2 | ⊢ ( 𝐹  ∈  ( 𝑀  GrpHom  𝑁 )  →  𝑁  ∈  Grp ) | 
						
							| 3 | 1 2 | syl | ⊢ ( 𝐹  ∈  ( 𝑀  GrpIso  𝑁 )  →  𝑁  ∈  Grp ) | 
						
							| 4 | 3 | adantl | ⊢ ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  →  𝑁  ∈  Grp ) | 
						
							| 5 | 4 | grpmndd | ⊢ ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  →  𝑁  ∈  Mnd ) | 
						
							| 6 |  | simpll | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  𝑀  ∈  Abel ) | 
						
							| 7 |  | eqid | ⊢ ( Base ‘ 𝑀 )  =  ( Base ‘ 𝑀 ) | 
						
							| 8 |  | eqid | ⊢ ( Base ‘ 𝑁 )  =  ( Base ‘ 𝑁 ) | 
						
							| 9 | 7 8 | gimf1o | ⊢ ( 𝐹  ∈  ( 𝑀  GrpIso  𝑁 )  →  𝐹 : ( Base ‘ 𝑀 ) –1-1-onto→ ( Base ‘ 𝑁 ) ) | 
						
							| 10 |  | f1ocnv | ⊢ ( 𝐹 : ( Base ‘ 𝑀 ) –1-1-onto→ ( Base ‘ 𝑁 )  →  ◡ 𝐹 : ( Base ‘ 𝑁 ) –1-1-onto→ ( Base ‘ 𝑀 ) ) | 
						
							| 11 |  | f1of | ⊢ ( ◡ 𝐹 : ( Base ‘ 𝑁 ) –1-1-onto→ ( Base ‘ 𝑀 )  →  ◡ 𝐹 : ( Base ‘ 𝑁 ) ⟶ ( Base ‘ 𝑀 ) ) | 
						
							| 12 | 9 10 11 | 3syl | ⊢ ( 𝐹  ∈  ( 𝑀  GrpIso  𝑁 )  →  ◡ 𝐹 : ( Base ‘ 𝑁 ) ⟶ ( Base ‘ 𝑀 ) ) | 
						
							| 13 | 12 | ad2antlr | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ◡ 𝐹 : ( Base ‘ 𝑁 ) ⟶ ( Base ‘ 𝑀 ) ) | 
						
							| 14 |  | simprl | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  𝑥  ∈  ( Base ‘ 𝑁 ) ) | 
						
							| 15 | 13 14 | ffvelcdmd | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ( Base ‘ 𝑀 ) ) | 
						
							| 16 |  | simprr | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  𝑦  ∈  ( Base ‘ 𝑁 ) ) | 
						
							| 17 | 13 16 | ffvelcdmd | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( ◡ 𝐹 ‘ 𝑦 )  ∈  ( Base ‘ 𝑀 ) ) | 
						
							| 18 |  | eqid | ⊢ ( +g ‘ 𝑀 )  =  ( +g ‘ 𝑀 ) | 
						
							| 19 | 7 18 | ablcom | ⊢ ( ( 𝑀  ∈  Abel  ∧  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ( Base ‘ 𝑀 )  ∧  ( ◡ 𝐹 ‘ 𝑦 )  ∈  ( Base ‘ 𝑀 ) )  →  ( ( ◡ 𝐹 ‘ 𝑥 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑦 ) )  =  ( ( ◡ 𝐹 ‘ 𝑦 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 20 | 6 15 17 19 | syl3anc | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( ( ◡ 𝐹 ‘ 𝑥 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑦 ) )  =  ( ( ◡ 𝐹 ‘ 𝑦 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 21 |  | gimcnv | ⊢ ( 𝐹  ∈  ( 𝑀  GrpIso  𝑁 )  →  ◡ 𝐹  ∈  ( 𝑁  GrpIso  𝑀 ) ) | 
						
							| 22 | 21 | ad2antlr | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ◡ 𝐹  ∈  ( 𝑁  GrpIso  𝑀 ) ) | 
						
							| 23 |  | gimghm | ⊢ ( ◡ 𝐹  ∈  ( 𝑁  GrpIso  𝑀 )  →  ◡ 𝐹  ∈  ( 𝑁  GrpHom  𝑀 ) ) | 
						
							| 24 | 22 23 | syl | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ◡ 𝐹  ∈  ( 𝑁  GrpHom  𝑀 ) ) | 
						
							| 25 |  | eqid | ⊢ ( +g ‘ 𝑁 )  =  ( +g ‘ 𝑁 ) | 
						
							| 26 | 8 25 18 | ghmlin | ⊢ ( ( ◡ 𝐹  ∈  ( 𝑁  GrpHom  𝑀 )  ∧  𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) )  →  ( ◡ 𝐹 ‘ ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) )  =  ( ( ◡ 𝐹 ‘ 𝑥 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑦 ) ) ) | 
						
							| 27 | 24 14 16 26 | syl3anc | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( ◡ 𝐹 ‘ ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) )  =  ( ( ◡ 𝐹 ‘ 𝑥 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑦 ) ) ) | 
						
							| 28 | 8 25 18 | ghmlin | ⊢ ( ( ◡ 𝐹  ∈  ( 𝑁  GrpHom  𝑀 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 )  ∧  𝑥  ∈  ( Base ‘ 𝑁 ) )  →  ( ◡ 𝐹 ‘ ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) )  =  ( ( ◡ 𝐹 ‘ 𝑦 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 29 | 24 16 14 28 | syl3anc | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( ◡ 𝐹 ‘ ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) )  =  ( ( ◡ 𝐹 ‘ 𝑦 ) ( +g ‘ 𝑀 ) ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 30 | 20 27 29 | 3eqtr4d | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( ◡ 𝐹 ‘ ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) )  =  ( ◡ 𝐹 ‘ ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) ) | 
						
							| 31 | 30 | fveq2d | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) ) )  =  ( 𝐹 ‘ ( ◡ 𝐹 ‘ ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) ) ) | 
						
							| 32 | 9 | ad2antlr | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  𝐹 : ( Base ‘ 𝑀 ) –1-1-onto→ ( Base ‘ 𝑁 ) ) | 
						
							| 33 | 3 | ad2antlr | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  𝑁  ∈  Grp ) | 
						
							| 34 | 8 25 | grpcl | ⊢ ( ( 𝑁  ∈  Grp  ∧  𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) )  →  ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 )  ∈  ( Base ‘ 𝑁 ) ) | 
						
							| 35 | 33 14 16 34 | syl3anc | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 )  ∈  ( Base ‘ 𝑁 ) ) | 
						
							| 36 |  | f1ocnvfv2 | ⊢ ( ( 𝐹 : ( Base ‘ 𝑀 ) –1-1-onto→ ( Base ‘ 𝑁 )  ∧  ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 )  ∈  ( Base ‘ 𝑁 ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) ) )  =  ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) ) | 
						
							| 37 | 32 35 36 | syl2anc | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) ) )  =  ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 ) ) | 
						
							| 38 | 8 25 | grpcl | ⊢ ( ( 𝑁  ∈  Grp  ∧  𝑦  ∈  ( Base ‘ 𝑁 )  ∧  𝑥  ∈  ( Base ‘ 𝑁 ) )  →  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 )  ∈  ( Base ‘ 𝑁 ) ) | 
						
							| 39 | 33 16 14 38 | syl3anc | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 )  ∈  ( Base ‘ 𝑁 ) ) | 
						
							| 40 |  | f1ocnvfv2 | ⊢ ( ( 𝐹 : ( Base ‘ 𝑀 ) –1-1-onto→ ( Base ‘ 𝑁 )  ∧  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 )  ∈  ( Base ‘ 𝑁 ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) )  =  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) | 
						
							| 41 | 32 39 40 | syl2anc | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) )  =  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) | 
						
							| 42 | 31 37 41 | 3eqtr3d | ⊢ ( ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  ∧  ( 𝑥  ∈  ( Base ‘ 𝑁 )  ∧  𝑦  ∈  ( Base ‘ 𝑁 ) ) )  →  ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) | 
						
							| 43 | 42 | ralrimivva | ⊢ ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  →  ∀ 𝑥  ∈  ( Base ‘ 𝑁 ) ∀ 𝑦  ∈  ( Base ‘ 𝑁 ) ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) | 
						
							| 44 | 8 25 | iscmn | ⊢ ( 𝑁  ∈  CMnd  ↔  ( 𝑁  ∈  Mnd  ∧  ∀ 𝑥  ∈  ( Base ‘ 𝑁 ) ∀ 𝑦  ∈  ( Base ‘ 𝑁 ) ( 𝑥 ( +g ‘ 𝑁 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑁 ) 𝑥 ) ) ) | 
						
							| 45 | 5 43 44 | sylanbrc | ⊢ ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  →  𝑁  ∈  CMnd ) | 
						
							| 46 |  | isabl | ⊢ ( 𝑁  ∈  Abel  ↔  ( 𝑁  ∈  Grp  ∧  𝑁  ∈  CMnd ) ) | 
						
							| 47 | 4 45 46 | sylanbrc | ⊢ ( ( 𝑀  ∈  Abel  ∧  𝐹  ∈  ( 𝑀  GrpIso  𝑁 ) )  →  𝑁  ∈  Abel ) |