| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ufilfil |  | 
						
							| 2 | 1 | 3ad2ant1 |  | 
						
							| 3 | 2 | adantr |  | 
						
							| 4 |  | simpr |  | 
						
							| 5 |  | unss |  | 
						
							| 6 | 5 | biimpi |  | 
						
							| 7 | 6 | 3adant1 |  | 
						
							| 8 | 7 | adantr |  | 
						
							| 9 |  | ssun1 |  | 
						
							| 10 | 9 | a1i |  | 
						
							| 11 |  | filss |  | 
						
							| 12 | 3 4 8 10 11 | syl13anc |  | 
						
							| 13 | 12 | ex |  | 
						
							| 14 | 2 | adantr |  | 
						
							| 15 |  | simpr |  | 
						
							| 16 | 7 | adantr |  | 
						
							| 17 |  | ssun2 |  | 
						
							| 18 | 17 | a1i |  | 
						
							| 19 |  | filss |  | 
						
							| 20 | 14 15 16 18 19 | syl13anc |  | 
						
							| 21 | 20 | ex |  | 
						
							| 22 | 13 21 | jaod |  | 
						
							| 23 |  | ufilb |  | 
						
							| 24 | 23 | 3adant3 |  | 
						
							| 25 | 24 | adantr |  | 
						
							| 26 | 2 | 3ad2ant1 |  | 
						
							| 27 |  | difun2 |  | 
						
							| 28 |  | uncom |  | 
						
							| 29 | 28 | difeq1i |  | 
						
							| 30 | 27 29 | eqtr3i |  | 
						
							| 31 | 30 | ineq2i |  | 
						
							| 32 |  | indifcom |  | 
						
							| 33 |  | indifcom |  | 
						
							| 34 | 31 32 33 | 3eqtr4i |  | 
						
							| 35 |  | filin |  | 
						
							| 36 | 2 35 | syl3an1 |  | 
						
							| 37 | 34 36 | eqeltrid |  | 
						
							| 38 |  | simp13 |  | 
						
							| 39 |  | inss1 |  | 
						
							| 40 | 39 | a1i |  | 
						
							| 41 |  | filss |  | 
						
							| 42 | 26 37 38 40 41 | syl13anc |  | 
						
							| 43 | 42 | 3expia |  | 
						
							| 44 | 25 43 | sylbid |  | 
						
							| 45 | 44 | orrd |  | 
						
							| 46 | 45 | ex |  | 
						
							| 47 | 22 46 | impbid |  |