| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ablsubadd.b | ⊢ 𝐵  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | ablsubadd.p | ⊢  +   =  ( +g ‘ 𝐺 ) | 
						
							| 3 |  | ablsubadd.m | ⊢  −   =  ( -g ‘ 𝐺 ) | 
						
							| 4 |  | ablgrp | ⊢ ( 𝐺  ∈  Abel  →  𝐺  ∈  Grp ) | 
						
							| 5 | 4 | 3ad2ant1 | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  𝐺  ∈  Grp ) | 
						
							| 6 |  | simp2l | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 7 |  | simp2r | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  𝑌  ∈  𝐵 ) | 
						
							| 8 | 1 2 | grpcl | ⊢ ( ( 𝐺  ∈  Grp  ∧  𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  →  ( 𝑋  +  𝑌 )  ∈  𝐵 ) | 
						
							| 9 | 5 6 7 8 | syl3anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( 𝑋  +  𝑌 )  ∈  𝐵 ) | 
						
							| 10 |  | simp3l | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  𝑍  ∈  𝐵 ) | 
						
							| 11 |  | simp3r | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  𝑊  ∈  𝐵 ) | 
						
							| 12 | 1 2 | grpcl | ⊢ ( ( 𝐺  ∈  Grp  ∧  𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 )  →  ( 𝑍  +  𝑊 )  ∈  𝐵 ) | 
						
							| 13 | 5 10 11 12 | syl3anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( 𝑍  +  𝑊 )  ∈  𝐵 ) | 
						
							| 14 |  | eqid | ⊢ ( invg ‘ 𝐺 )  =  ( invg ‘ 𝐺 ) | 
						
							| 15 | 1 2 14 3 | grpsubval | ⊢ ( ( ( 𝑋  +  𝑌 )  ∈  𝐵  ∧  ( 𝑍  +  𝑊 )  ∈  𝐵 )  →  ( ( 𝑋  +  𝑌 )  −  ( 𝑍  +  𝑊 ) )  =  ( ( 𝑋  +  𝑌 )  +  ( ( invg ‘ 𝐺 ) ‘ ( 𝑍  +  𝑊 ) ) ) ) | 
						
							| 16 | 9 13 15 | syl2anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( 𝑋  +  𝑌 )  −  ( 𝑍  +  𝑊 ) )  =  ( ( 𝑋  +  𝑌 )  +  ( ( invg ‘ 𝐺 ) ‘ ( 𝑍  +  𝑊 ) ) ) ) | 
						
							| 17 |  | ablcmn | ⊢ ( 𝐺  ∈  Abel  →  𝐺  ∈  CMnd ) | 
						
							| 18 | 17 | 3ad2ant1 | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  𝐺  ∈  CMnd ) | 
						
							| 19 |  | simp2 | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 ) ) | 
						
							| 20 | 1 14 | grpinvcl | ⊢ ( ( 𝐺  ∈  Grp  ∧  𝑍  ∈  𝐵 )  →  ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  ∈  𝐵 ) | 
						
							| 21 | 5 10 20 | syl2anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  ∈  𝐵 ) | 
						
							| 22 | 1 14 | grpinvcl | ⊢ ( ( 𝐺  ∈  Grp  ∧  𝑊  ∈  𝐵 )  →  ( ( invg ‘ 𝐺 ) ‘ 𝑊 )  ∈  𝐵 ) | 
						
							| 23 | 5 11 22 | syl2anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( invg ‘ 𝐺 ) ‘ 𝑊 )  ∈  𝐵 ) | 
						
							| 24 | 1 2 | cmn4 | ⊢ ( ( 𝐺  ∈  CMnd  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  ∈  𝐵  ∧  ( ( invg ‘ 𝐺 ) ‘ 𝑊 )  ∈  𝐵 ) )  →  ( ( 𝑋  +  𝑌 )  +  ( ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) )  =  ( ( 𝑋  +  ( ( invg ‘ 𝐺 ) ‘ 𝑍 ) )  +  ( 𝑌  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) ) | 
						
							| 25 | 18 19 21 23 24 | syl112anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( 𝑋  +  𝑌 )  +  ( ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) )  =  ( ( 𝑋  +  ( ( invg ‘ 𝐺 ) ‘ 𝑍 ) )  +  ( 𝑌  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) ) | 
						
							| 26 |  | simp1 | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  𝐺  ∈  Abel ) | 
						
							| 27 | 1 2 14 | ablinvadd | ⊢ ( ( 𝐺  ∈  Abel  ∧  𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 )  →  ( ( invg ‘ 𝐺 ) ‘ ( 𝑍  +  𝑊 ) )  =  ( ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) | 
						
							| 28 | 26 10 11 27 | syl3anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( invg ‘ 𝐺 ) ‘ ( 𝑍  +  𝑊 ) )  =  ( ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) | 
						
							| 29 | 28 | oveq2d | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( 𝑋  +  𝑌 )  +  ( ( invg ‘ 𝐺 ) ‘ ( 𝑍  +  𝑊 ) ) )  =  ( ( 𝑋  +  𝑌 )  +  ( ( ( invg ‘ 𝐺 ) ‘ 𝑍 )  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) ) | 
						
							| 30 | 1 2 14 3 | grpsubval | ⊢ ( ( 𝑋  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  →  ( 𝑋  −  𝑍 )  =  ( 𝑋  +  ( ( invg ‘ 𝐺 ) ‘ 𝑍 ) ) ) | 
						
							| 31 | 6 10 30 | syl2anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( 𝑋  −  𝑍 )  =  ( 𝑋  +  ( ( invg ‘ 𝐺 ) ‘ 𝑍 ) ) ) | 
						
							| 32 | 1 2 14 3 | grpsubval | ⊢ ( ( 𝑌  ∈  𝐵  ∧  𝑊  ∈  𝐵 )  →  ( 𝑌  −  𝑊 )  =  ( 𝑌  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) | 
						
							| 33 | 7 11 32 | syl2anc | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( 𝑌  −  𝑊 )  =  ( 𝑌  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) | 
						
							| 34 | 31 33 | oveq12d | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( 𝑋  −  𝑍 )  +  ( 𝑌  −  𝑊 ) )  =  ( ( 𝑋  +  ( ( invg ‘ 𝐺 ) ‘ 𝑍 ) )  +  ( 𝑌  +  ( ( invg ‘ 𝐺 ) ‘ 𝑊 ) ) ) ) | 
						
							| 35 | 25 29 34 | 3eqtr4d | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( 𝑋  +  𝑌 )  +  ( ( invg ‘ 𝐺 ) ‘ ( 𝑍  +  𝑊 ) ) )  =  ( ( 𝑋  −  𝑍 )  +  ( 𝑌  −  𝑊 ) ) ) | 
						
							| 36 | 16 35 | eqtrd | ⊢ ( ( 𝐺  ∈  Abel  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  ( 𝑍  ∈  𝐵  ∧  𝑊  ∈  𝐵 ) )  →  ( ( 𝑋  +  𝑌 )  −  ( 𝑍  +  𝑊 ) )  =  ( ( 𝑋  −  𝑍 )  +  ( 𝑌  −  𝑊 ) ) ) |