| Step | Hyp | Ref | Expression | 
						
							| 1 |  | hoaddrid.1 | ⊢ 𝑇 :  ℋ ⟶  ℋ | 
						
							| 2 |  | ho0f | ⊢  0hop  :  ℋ ⟶  ℋ | 
						
							| 3 |  | hosval | ⊢ ( ( 𝑇 :  ℋ ⟶  ℋ  ∧   0hop  :  ℋ ⟶  ℋ  ∧  𝑥  ∈   ℋ )  →  ( ( 𝑇  +op   0hop  ) ‘ 𝑥 )  =  ( ( 𝑇 ‘ 𝑥 )  +ℎ  (  0hop  ‘ 𝑥 ) ) ) | 
						
							| 4 | 1 2 3 | mp3an12 | ⊢ ( 𝑥  ∈   ℋ  →  ( ( 𝑇  +op   0hop  ) ‘ 𝑥 )  =  ( ( 𝑇 ‘ 𝑥 )  +ℎ  (  0hop  ‘ 𝑥 ) ) ) | 
						
							| 5 |  | ho0val | ⊢ ( 𝑥  ∈   ℋ  →  (  0hop  ‘ 𝑥 )  =  0ℎ ) | 
						
							| 6 | 5 | oveq2d | ⊢ ( 𝑥  ∈   ℋ  →  ( ( 𝑇 ‘ 𝑥 )  +ℎ  (  0hop  ‘ 𝑥 ) )  =  ( ( 𝑇 ‘ 𝑥 )  +ℎ  0ℎ ) ) | 
						
							| 7 | 1 | ffvelcdmi | ⊢ ( 𝑥  ∈   ℋ  →  ( 𝑇 ‘ 𝑥 )  ∈   ℋ ) | 
						
							| 8 |  | ax-hvaddid | ⊢ ( ( 𝑇 ‘ 𝑥 )  ∈   ℋ  →  ( ( 𝑇 ‘ 𝑥 )  +ℎ  0ℎ )  =  ( 𝑇 ‘ 𝑥 ) ) | 
						
							| 9 | 7 8 | syl | ⊢ ( 𝑥  ∈   ℋ  →  ( ( 𝑇 ‘ 𝑥 )  +ℎ  0ℎ )  =  ( 𝑇 ‘ 𝑥 ) ) | 
						
							| 10 | 4 6 9 | 3eqtrd | ⊢ ( 𝑥  ∈   ℋ  →  ( ( 𝑇  +op   0hop  ) ‘ 𝑥 )  =  ( 𝑇 ‘ 𝑥 ) ) | 
						
							| 11 | 10 | rgen | ⊢ ∀ 𝑥  ∈   ℋ ( ( 𝑇  +op   0hop  ) ‘ 𝑥 )  =  ( 𝑇 ‘ 𝑥 ) | 
						
							| 12 | 1 2 | hoaddcli | ⊢ ( 𝑇  +op   0hop  ) :  ℋ ⟶  ℋ | 
						
							| 13 | 12 1 | hoeqi | ⊢ ( ∀ 𝑥  ∈   ℋ ( ( 𝑇  +op   0hop  ) ‘ 𝑥 )  =  ( 𝑇 ‘ 𝑥 )  ↔  ( 𝑇  +op   0hop  )  =  𝑇 ) | 
						
							| 14 | 11 13 | mpbi | ⊢ ( 𝑇  +op   0hop  )  =  𝑇 |