| Step | Hyp | Ref | Expression | 
						
							| 1 |  | bnj873.4 |  | 
						
							| 2 |  | bnj873.7 | Could not format  ( ph' <-> [. g / f ]. ph ) : No typesetting found for |- ( ph' <-> [. g / f ]. ph ) with typecode |- | 
						
							| 3 |  | bnj873.8 | Could not format  ( ps' <-> [. g / f ]. ps ) : No typesetting found for |- ( ps' <-> [. g / f ]. ps ) with typecode |- | 
						
							| 4 |  | nfv |  | 
						
							| 5 |  | nfcv |  | 
						
							| 6 |  | nfv |  | 
						
							| 7 |  | nfsbc1v |  | 
						
							| 8 | 2 7 | nfxfr | Could not format  F/ f ph' : No typesetting found for |- F/ f ph' with typecode |- | 
						
							| 9 |  | nfsbc1v |  | 
						
							| 10 | 3 9 | nfxfr | Could not format  F/ f ps' : No typesetting found for |- F/ f ps' with typecode |- | 
						
							| 11 | 6 8 10 | nf3an | Could not format  F/ f ( g Fn n /\ ph' /\ ps' ) : No typesetting found for |- F/ f ( g Fn n /\ ph' /\ ps' ) with typecode |- | 
						
							| 12 | 5 11 | nfrexw | Could not format  F/ f E. n e. D ( g Fn n /\ ph' /\ ps' ) : No typesetting found for |- F/ f E. n e. D ( g Fn n /\ ph' /\ ps' ) with typecode |- | 
						
							| 13 |  | fneq1 |  | 
						
							| 14 |  | sbceq1a |  | 
						
							| 15 | 14 2 | bitr4di | Could not format  ( f = g -> ( ph <-> ph' ) ) : No typesetting found for |- ( f = g -> ( ph <-> ph' ) ) with typecode |- | 
						
							| 16 |  | sbceq1a |  | 
						
							| 17 | 16 3 | bitr4di | Could not format  ( f = g -> ( ps <-> ps' ) ) : No typesetting found for |- ( f = g -> ( ps <-> ps' ) ) with typecode |- | 
						
							| 18 | 13 15 17 | 3anbi123d | Could not format  ( f = g -> ( ( f Fn n /\ ph /\ ps ) <-> ( g Fn n /\ ph' /\ ps' ) ) ) : No typesetting found for |- ( f = g -> ( ( f Fn n /\ ph /\ ps ) <-> ( g Fn n /\ ph' /\ ps' ) ) ) with typecode |- | 
						
							| 19 | 18 | rexbidv | Could not format  ( f = g -> ( E. n e. D ( f Fn n /\ ph /\ ps ) <-> E. n e. D ( g Fn n /\ ph' /\ ps' ) ) ) : No typesetting found for |- ( f = g -> ( E. n e. D ( f Fn n /\ ph /\ ps ) <-> E. n e. D ( g Fn n /\ ph' /\ ps' ) ) ) with typecode |- | 
						
							| 20 | 4 12 19 | cbvabw | Could not format  { f | E. n e. D ( f Fn n /\ ph /\ ps ) } = { g | E. n e. D ( g Fn n /\ ph' /\ ps' ) } : No typesetting found for |- { f | E. n e. D ( f Fn n /\ ph /\ ps ) } = { g | E. n e. D ( g Fn n /\ ph' /\ ps' ) } with typecode |- | 
						
							| 21 | 1 20 | eqtri | Could not format  B = { g | E. n e. D ( g Fn n /\ ph' /\ ps' ) } : No typesetting found for |- B = { g | E. n e. D ( g Fn n /\ ph' /\ ps' ) } with typecode |- |