| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sbthlem.1 | ⊢ 𝐴  ∈  V | 
						
							| 2 |  | sbthlem.2 | ⊢ 𝐷  =  { 𝑥  ∣  ( 𝑥  ⊆  𝐴  ∧  ( 𝑔  “  ( 𝐵  ∖  ( 𝑓  “  𝑥 ) ) )  ⊆  ( 𝐴  ∖  𝑥 ) ) } | 
						
							| 3 |  | sbthlem.3 | ⊢ 𝐻  =  ( ( 𝑓  ↾  ∪  𝐷 )  ∪  ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) | 
						
							| 4 |  | funres11 | ⊢ ( Fun  ◡ 𝑓  →  Fun  ◡ ( 𝑓  ↾  ∪  𝐷 ) ) | 
						
							| 5 |  | funcnvcnv | ⊢ ( Fun  𝑔  →  Fun  ◡ ◡ 𝑔 ) | 
						
							| 6 |  | funres11 | ⊢ ( Fun  ◡ ◡ 𝑔  →  Fun  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) | 
						
							| 7 | 5 6 | syl | ⊢ ( Fun  𝑔  →  Fun  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) | 
						
							| 8 | 7 | ad3antrrr | ⊢ ( ( ( ( Fun  𝑔  ∧  dom  𝑔  =  𝐵 )  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 )  →  Fun  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) | 
						
							| 9 | 4 8 | anim12i | ⊢ ( ( Fun  ◡ 𝑓  ∧  ( ( ( Fun  𝑔  ∧  dom  𝑔  =  𝐵 )  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 ) )  →  ( Fun  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∧  Fun  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) ) | 
						
							| 10 |  | df-ima | ⊢ ( 𝑓  “  ∪  𝐷 )  =  ran  ( 𝑓  ↾  ∪  𝐷 ) | 
						
							| 11 |  | df-rn | ⊢ ran  ( 𝑓  ↾  ∪  𝐷 )  =  dom  ◡ ( 𝑓  ↾  ∪  𝐷 ) | 
						
							| 12 | 10 11 | eqtr2i | ⊢ dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  =  ( 𝑓  “  ∪  𝐷 ) | 
						
							| 13 |  | df-ima | ⊢ ( ◡ 𝑔  “  ( 𝐴  ∖  ∪  𝐷 ) )  =  ran  ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) | 
						
							| 14 |  | df-rn | ⊢ ran  ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) )  =  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) | 
						
							| 15 | 13 14 | eqtri | ⊢ ( ◡ 𝑔  “  ( 𝐴  ∖  ∪  𝐷 ) )  =  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) | 
						
							| 16 | 1 2 | sbthlem4 | ⊢ ( ( ( dom  𝑔  =  𝐵  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 )  →  ( ◡ 𝑔  “  ( 𝐴  ∖  ∪  𝐷 ) )  =  ( 𝐵  ∖  ( 𝑓  “  ∪  𝐷 ) ) ) | 
						
							| 17 | 15 16 | eqtr3id | ⊢ ( ( ( dom  𝑔  =  𝐵  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 )  →  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) )  =  ( 𝐵  ∖  ( 𝑓  “  ∪  𝐷 ) ) ) | 
						
							| 18 |  | ineq12 | ⊢ ( ( dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  =  ( 𝑓  “  ∪  𝐷 )  ∧  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) )  =  ( 𝐵  ∖  ( 𝑓  “  ∪  𝐷 ) ) )  →  ( dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∩  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  =  ( ( 𝑓  “  ∪  𝐷 )  ∩  ( 𝐵  ∖  ( 𝑓  “  ∪  𝐷 ) ) ) ) | 
						
							| 19 | 12 17 18 | sylancr | ⊢ ( ( ( dom  𝑔  =  𝐵  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 )  →  ( dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∩  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  =  ( ( 𝑓  “  ∪  𝐷 )  ∩  ( 𝐵  ∖  ( 𝑓  “  ∪  𝐷 ) ) ) ) | 
						
							| 20 |  | disjdif | ⊢ ( ( 𝑓  “  ∪  𝐷 )  ∩  ( 𝐵  ∖  ( 𝑓  “  ∪  𝐷 ) ) )  =  ∅ | 
						
							| 21 | 19 20 | eqtrdi | ⊢ ( ( ( dom  𝑔  =  𝐵  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 )  →  ( dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∩  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  =  ∅ ) | 
						
							| 22 | 21 | adantlll | ⊢ ( ( ( ( Fun  𝑔  ∧  dom  𝑔  =  𝐵 )  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 )  →  ( dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∩  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  =  ∅ ) | 
						
							| 23 | 22 | adantl | ⊢ ( ( Fun  ◡ 𝑓  ∧  ( ( ( Fun  𝑔  ∧  dom  𝑔  =  𝐵 )  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 ) )  →  ( dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∩  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  =  ∅ ) | 
						
							| 24 |  | funun | ⊢ ( ( ( Fun  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∧  Fun  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  ∧  ( dom  ◡ ( 𝑓  ↾  ∪  𝐷 )  ∩  dom  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  =  ∅ )  →  Fun  ( ◡ ( 𝑓  ↾  ∪  𝐷 )  ∪  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) ) | 
						
							| 25 | 9 23 24 | syl2anc | ⊢ ( ( Fun  ◡ 𝑓  ∧  ( ( ( Fun  𝑔  ∧  dom  𝑔  =  𝐵 )  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 ) )  →  Fun  ( ◡ ( 𝑓  ↾  ∪  𝐷 )  ∪  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) ) | 
						
							| 26 | 3 | cnveqi | ⊢ ◡ 𝐻  =  ◡ ( ( 𝑓  ↾  ∪  𝐷 )  ∪  ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) | 
						
							| 27 |  | cnvun | ⊢ ◡ ( ( 𝑓  ↾  ∪  𝐷 )  ∪  ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) )  =  ( ◡ ( 𝑓  ↾  ∪  𝐷 )  ∪  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) | 
						
							| 28 | 26 27 | eqtri | ⊢ ◡ 𝐻  =  ( ◡ ( 𝑓  ↾  ∪  𝐷 )  ∪  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) | 
						
							| 29 | 28 | funeqi | ⊢ ( Fun  ◡ 𝐻  ↔  Fun  ( ◡ ( 𝑓  ↾  ∪  𝐷 )  ∪  ◡ ( ◡ 𝑔  ↾  ( 𝐴  ∖  ∪  𝐷 ) ) ) ) | 
						
							| 30 | 25 29 | sylibr | ⊢ ( ( Fun  ◡ 𝑓  ∧  ( ( ( Fun  𝑔  ∧  dom  𝑔  =  𝐵 )  ∧  ran  𝑔  ⊆  𝐴 )  ∧  Fun  ◡ 𝑔 ) )  →  Fun  ◡ 𝐻 ) |