| Step | Hyp | Ref | Expression | 
						
							| 1 |  | gsummptfzcl.b | ⊢ 𝐵  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | gsummptfzcl.g | ⊢ ( 𝜑  →  𝐺  ∈  Mnd ) | 
						
							| 3 |  | gsummptfzcl.n | ⊢ ( 𝜑  →  𝑁  ∈  ( ℤ≥ ‘ 𝑀 ) ) | 
						
							| 4 |  | gsummptfzcl.i | ⊢ ( 𝜑  →  𝐼  =  ( 𝑀 ... 𝑁 ) ) | 
						
							| 5 |  | gsummptfzcl.e | ⊢ ( 𝜑  →  ∀ 𝑖  ∈  𝐼 𝑋  ∈  𝐵 ) | 
						
							| 6 |  | eqid | ⊢ ( +g ‘ 𝐺 )  =  ( +g ‘ 𝐺 ) | 
						
							| 7 |  | eqid | ⊢ ( 𝑖  ∈  𝐼  ↦  𝑋 )  =  ( 𝑖  ∈  𝐼  ↦  𝑋 ) | 
						
							| 8 | 7 | fmpt | ⊢ ( ∀ 𝑖  ∈  𝐼 𝑋  ∈  𝐵  ↔  ( 𝑖  ∈  𝐼  ↦  𝑋 ) : 𝐼 ⟶ 𝐵 ) | 
						
							| 9 | 4 | feq2d | ⊢ ( 𝜑  →  ( ( 𝑖  ∈  𝐼  ↦  𝑋 ) : 𝐼 ⟶ 𝐵  ↔  ( 𝑖  ∈  𝐼  ↦  𝑋 ) : ( 𝑀 ... 𝑁 ) ⟶ 𝐵 ) ) | 
						
							| 10 | 8 9 | bitrid | ⊢ ( 𝜑  →  ( ∀ 𝑖  ∈  𝐼 𝑋  ∈  𝐵  ↔  ( 𝑖  ∈  𝐼  ↦  𝑋 ) : ( 𝑀 ... 𝑁 ) ⟶ 𝐵 ) ) | 
						
							| 11 | 5 10 | mpbid | ⊢ ( 𝜑  →  ( 𝑖  ∈  𝐼  ↦  𝑋 ) : ( 𝑀 ... 𝑁 ) ⟶ 𝐵 ) | 
						
							| 12 | 1 6 2 3 11 | gsumval2 | ⊢ ( 𝜑  →  ( 𝐺  Σg  ( 𝑖  ∈  𝐼  ↦  𝑋 ) )  =  ( seq 𝑀 ( ( +g ‘ 𝐺 ) ,  ( 𝑖  ∈  𝐼  ↦  𝑋 ) ) ‘ 𝑁 ) ) | 
						
							| 13 | 5 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  ∀ 𝑖  ∈  𝐼 𝑋  ∈  𝐵 ) | 
						
							| 14 | 13 8 | sylib | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝑖  ∈  𝐼  ↦  𝑋 ) : 𝐼 ⟶ 𝐵 ) | 
						
							| 15 | 4 | eqcomd | ⊢ ( 𝜑  →  ( 𝑀 ... 𝑁 )  =  𝐼 ) | 
						
							| 16 | 15 | eleq2d | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ↔  𝑥  ∈  𝐼 ) ) | 
						
							| 17 | 16 | biimpa | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  𝑥  ∈  𝐼 ) | 
						
							| 18 | 14 17 | ffvelcdmd | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  ( ( 𝑖  ∈  𝐼  ↦  𝑋 ) ‘ 𝑥 )  ∈  𝐵 ) | 
						
							| 19 | 2 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  𝐺  ∈  Mnd ) | 
						
							| 20 |  | simprl | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  𝑥  ∈  𝐵 ) | 
						
							| 21 |  | simprr | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  𝑦  ∈  𝐵 ) | 
						
							| 22 | 1 6 | mndcl | ⊢ ( ( 𝐺  ∈  Mnd  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 )  →  ( 𝑥 ( +g ‘ 𝐺 ) 𝑦 )  ∈  𝐵 ) | 
						
							| 23 | 19 20 21 22 | syl3anc | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  ( 𝑥 ( +g ‘ 𝐺 ) 𝑦 )  ∈  𝐵 ) | 
						
							| 24 | 3 18 23 | seqcl | ⊢ ( 𝜑  →  ( seq 𝑀 ( ( +g ‘ 𝐺 ) ,  ( 𝑖  ∈  𝐼  ↦  𝑋 ) ) ‘ 𝑁 )  ∈  𝐵 ) | 
						
							| 25 | 12 24 | eqeltrd | ⊢ ( 𝜑  →  ( 𝐺  Σg  ( 𝑖  ∈  𝐼  ↦  𝑋 ) )  ∈  𝐵 ) |