| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mulgnndir.b | ⊢ 𝐵  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | mulgnndir.t | ⊢  ·   =  ( .g ‘ 𝐺 ) | 
						
							| 3 |  | mulgnndir.p | ⊢  +   =  ( +g ‘ 𝐺 ) | 
						
							| 4 |  | sgrpmgm | ⊢ ( 𝐺  ∈  Smgrp  →  𝐺  ∈  Mgm ) | 
						
							| 5 | 1 3 | mgmcl | ⊢ ( ( 𝐺  ∈  Mgm  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  →  ( 𝑥  +  𝑦 )  ∈  𝐵 ) | 
						
							| 6 | 4 5 | syl3an1 | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  →  ( 𝑥  +  𝑦 )  ∈  𝐵 ) | 
						
							| 7 | 6 | 3expb | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  ( 𝑥  +  𝑦 )  ∈  𝐵 ) | 
						
							| 8 | 7 | adantlr | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  ( 𝑥  +  𝑦 )  ∈  𝐵 ) | 
						
							| 9 | 1 3 | sgrpass | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵  ∧  𝑧  ∈  𝐵 ) )  →  ( ( 𝑥  +  𝑦 )  +  𝑧 )  =  ( 𝑥  +  ( 𝑦  +  𝑧 ) ) ) | 
						
							| 10 | 9 | adantlr | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵  ∧  𝑧  ∈  𝐵 ) )  →  ( ( 𝑥  +  𝑦 )  +  𝑧 )  =  ( 𝑥  +  ( 𝑦  +  𝑧 ) ) ) | 
						
							| 11 |  | simpr2 | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑁  ∈  ℕ ) | 
						
							| 12 |  | nnuz | ⊢ ℕ  =  ( ℤ≥ ‘ 1 ) | 
						
							| 13 | 11 12 | eleqtrdi | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑁  ∈  ( ℤ≥ ‘ 1 ) ) | 
						
							| 14 |  | simpr1 | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑀  ∈  ℕ ) | 
						
							| 15 | 14 | nnzd | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑀  ∈  ℤ ) | 
						
							| 16 |  | eluzadd | ⊢ ( ( 𝑁  ∈  ( ℤ≥ ‘ 1 )  ∧  𝑀  ∈  ℤ )  →  ( 𝑁  +  𝑀 )  ∈  ( ℤ≥ ‘ ( 1  +  𝑀 ) ) ) | 
						
							| 17 | 13 15 16 | syl2anc | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑁  +  𝑀 )  ∈  ( ℤ≥ ‘ ( 1  +  𝑀 ) ) ) | 
						
							| 18 | 14 | nncnd | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑀  ∈  ℂ ) | 
						
							| 19 | 11 | nncnd | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑁  ∈  ℂ ) | 
						
							| 20 | 18 19 | addcomd | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑀  +  𝑁 )  =  ( 𝑁  +  𝑀 ) ) | 
						
							| 21 |  | ax-1cn | ⊢ 1  ∈  ℂ | 
						
							| 22 |  | addcom | ⊢ ( ( 𝑀  ∈  ℂ  ∧  1  ∈  ℂ )  →  ( 𝑀  +  1 )  =  ( 1  +  𝑀 ) ) | 
						
							| 23 | 18 21 22 | sylancl | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑀  +  1 )  =  ( 1  +  𝑀 ) ) | 
						
							| 24 | 23 | fveq2d | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( ℤ≥ ‘ ( 𝑀  +  1 ) )  =  ( ℤ≥ ‘ ( 1  +  𝑀 ) ) ) | 
						
							| 25 | 17 20 24 | 3eltr4d | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑀  +  𝑁 )  ∈  ( ℤ≥ ‘ ( 𝑀  +  1 ) ) ) | 
						
							| 26 | 14 12 | eleqtrdi | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑀  ∈  ( ℤ≥ ‘ 1 ) ) | 
						
							| 27 |  | simpr3 | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 28 |  | elfznn | ⊢ ( 𝑥  ∈  ( 1 ... ( 𝑀  +  𝑁 ) )  →  𝑥  ∈  ℕ ) | 
						
							| 29 |  | fvconst2g | ⊢ ( ( 𝑋  ∈  𝐵  ∧  𝑥  ∈  ℕ )  →  ( ( ℕ  ×  { 𝑋 } ) ‘ 𝑥 )  =  𝑋 ) | 
						
							| 30 | 27 28 29 | syl2an | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  ( ( ℕ  ×  { 𝑋 } ) ‘ 𝑥 )  =  𝑋 ) | 
						
							| 31 | 27 | adantr | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 32 | 30 31 | eqeltrd | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  ( ( ℕ  ×  { 𝑋 } ) ‘ 𝑥 )  ∈  𝐵 ) | 
						
							| 33 | 8 10 25 26 32 | seqsplit | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑀  +  𝑁 ) )  =  ( ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ 𝑀 )  +  ( seq ( 𝑀  +  1 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑀  +  𝑁 ) ) ) ) | 
						
							| 34 |  | nnaddcl | ⊢ ( ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ )  →  ( 𝑀  +  𝑁 )  ∈  ℕ ) | 
						
							| 35 | 14 11 34 | syl2anc | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑀  +  𝑁 )  ∈  ℕ ) | 
						
							| 36 |  | eqid | ⊢ seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) )  =  seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) | 
						
							| 37 | 1 3 2 36 | mulgnn | ⊢ ( ( ( 𝑀  +  𝑁 )  ∈  ℕ  ∧  𝑋  ∈  𝐵 )  →  ( ( 𝑀  +  𝑁 )  ·  𝑋 )  =  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑀  +  𝑁 ) ) ) | 
						
							| 38 | 35 27 37 | syl2anc | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( ( 𝑀  +  𝑁 )  ·  𝑋 )  =  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑀  +  𝑁 ) ) ) | 
						
							| 39 | 1 3 2 36 | mulgnn | ⊢ ( ( 𝑀  ∈  ℕ  ∧  𝑋  ∈  𝐵 )  →  ( 𝑀  ·  𝑋 )  =  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ 𝑀 ) ) | 
						
							| 40 | 14 27 39 | syl2anc | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑀  ·  𝑋 )  =  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ 𝑀 ) ) | 
						
							| 41 |  | elfznn | ⊢ ( 𝑥  ∈  ( 1 ... 𝑁 )  →  𝑥  ∈  ℕ ) | 
						
							| 42 | 27 41 29 | syl2an | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... 𝑁 ) )  →  ( ( ℕ  ×  { 𝑋 } ) ‘ 𝑥 )  =  𝑋 ) | 
						
							| 43 | 27 | adantr | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... 𝑁 ) )  →  𝑋  ∈  𝐵 ) | 
						
							| 44 |  | nnaddcl | ⊢ ( ( 𝑥  ∈  ℕ  ∧  𝑀  ∈  ℕ )  →  ( 𝑥  +  𝑀 )  ∈  ℕ ) | 
						
							| 45 | 41 14 44 | syl2anr | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... 𝑁 ) )  →  ( 𝑥  +  𝑀 )  ∈  ℕ ) | 
						
							| 46 |  | fvconst2g | ⊢ ( ( 𝑋  ∈  𝐵  ∧  ( 𝑥  +  𝑀 )  ∈  ℕ )  →  ( ( ℕ  ×  { 𝑋 } ) ‘ ( 𝑥  +  𝑀 ) )  =  𝑋 ) | 
						
							| 47 | 43 45 46 | syl2anc | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... 𝑁 ) )  →  ( ( ℕ  ×  { 𝑋 } ) ‘ ( 𝑥  +  𝑀 ) )  =  𝑋 ) | 
						
							| 48 | 42 47 | eqtr4d | ⊢ ( ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  ∧  𝑥  ∈  ( 1 ... 𝑁 ) )  →  ( ( ℕ  ×  { 𝑋 } ) ‘ 𝑥 )  =  ( ( ℕ  ×  { 𝑋 } ) ‘ ( 𝑥  +  𝑀 ) ) ) | 
						
							| 49 | 13 15 48 | seqshft2 | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ 𝑁 )  =  ( seq ( 1  +  𝑀 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑁  +  𝑀 ) ) ) | 
						
							| 50 | 1 3 2 36 | mulgnn | ⊢ ( ( 𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 )  →  ( 𝑁  ·  𝑋 )  =  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ 𝑁 ) ) | 
						
							| 51 | 11 27 50 | syl2anc | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑁  ·  𝑋 )  =  ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ 𝑁 ) ) | 
						
							| 52 | 23 | seqeq1d | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  seq ( 𝑀  +  1 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) )  =  seq ( 1  +  𝑀 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ) | 
						
							| 53 | 52 20 | fveq12d | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( seq ( 𝑀  +  1 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑀  +  𝑁 ) )  =  ( seq ( 1  +  𝑀 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑁  +  𝑀 ) ) ) | 
						
							| 54 | 49 51 53 | 3eqtr4d | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( 𝑁  ·  𝑋 )  =  ( seq ( 𝑀  +  1 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑀  +  𝑁 ) ) ) | 
						
							| 55 | 40 54 | oveq12d | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( ( 𝑀  ·  𝑋 )  +  ( 𝑁  ·  𝑋 ) )  =  ( ( seq 1 (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ 𝑀 )  +  ( seq ( 𝑀  +  1 ) (  +  ,  ( ℕ  ×  { 𝑋 } ) ) ‘ ( 𝑀  +  𝑁 ) ) ) ) | 
						
							| 56 | 33 38 55 | 3eqtr4d | ⊢ ( ( 𝐺  ∈  Smgrp  ∧  ( 𝑀  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑋  ∈  𝐵 ) )  →  ( ( 𝑀  +  𝑁 )  ·  𝑋 )  =  ( ( 𝑀  ·  𝑋 )  +  ( 𝑁  ·  𝑋 ) ) ) |