| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lrrec.1 | ⊢ 𝑅  =  { 〈 𝑥 ,  𝑦 〉  ∣  𝑥  ∈  ( (  L  ‘ 𝑦 )  ∪  (  R  ‘ 𝑦 ) ) } | 
						
							| 2 |  | bdayelon | ⊢ (  bday  ‘ 𝑎 )  ∈  On | 
						
							| 3 | 2 | onirri | ⊢ ¬  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑎 ) | 
						
							| 4 | 1 | lrrecval2 | ⊢ ( ( 𝑎  ∈   No   ∧  𝑎  ∈   No  )  →  ( 𝑎 𝑅 𝑎  ↔  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑎 ) ) ) | 
						
							| 5 | 4 | anidms | ⊢ ( 𝑎  ∈   No   →  ( 𝑎 𝑅 𝑎  ↔  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑎 ) ) ) | 
						
							| 6 | 3 5 | mtbiri | ⊢ ( 𝑎  ∈   No   →  ¬  𝑎 𝑅 𝑎 ) | 
						
							| 7 | 6 | adantl | ⊢ ( ( ⊤  ∧  𝑎  ∈   No  )  →  ¬  𝑎 𝑅 𝑎 ) | 
						
							| 8 |  | bdayelon | ⊢ (  bday  ‘ 𝑐 )  ∈  On | 
						
							| 9 |  | ontr1 | ⊢ ( (  bday  ‘ 𝑐 )  ∈  On  →  ( ( (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑏 )  ∧  (  bday  ‘ 𝑏 )  ∈  (  bday  ‘ 𝑐 ) )  →  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑐 ) ) ) | 
						
							| 10 | 8 9 | ax-mp | ⊢ ( ( (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑏 )  ∧  (  bday  ‘ 𝑏 )  ∈  (  bday  ‘ 𝑐 ) )  →  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑐 ) ) | 
						
							| 11 | 1 | lrrecval2 | ⊢ ( ( 𝑎  ∈   No   ∧  𝑏  ∈   No  )  →  ( 𝑎 𝑅 𝑏  ↔  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑏 ) ) ) | 
						
							| 12 | 11 | 3adant3 | ⊢ ( ( 𝑎  ∈   No   ∧  𝑏  ∈   No   ∧  𝑐  ∈   No  )  →  ( 𝑎 𝑅 𝑏  ↔  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑏 ) ) ) | 
						
							| 13 | 1 | lrrecval2 | ⊢ ( ( 𝑏  ∈   No   ∧  𝑐  ∈   No  )  →  ( 𝑏 𝑅 𝑐  ↔  (  bday  ‘ 𝑏 )  ∈  (  bday  ‘ 𝑐 ) ) ) | 
						
							| 14 | 13 | 3adant1 | ⊢ ( ( 𝑎  ∈   No   ∧  𝑏  ∈   No   ∧  𝑐  ∈   No  )  →  ( 𝑏 𝑅 𝑐  ↔  (  bday  ‘ 𝑏 )  ∈  (  bday  ‘ 𝑐 ) ) ) | 
						
							| 15 | 12 14 | anbi12d | ⊢ ( ( 𝑎  ∈   No   ∧  𝑏  ∈   No   ∧  𝑐  ∈   No  )  →  ( ( 𝑎 𝑅 𝑏  ∧  𝑏 𝑅 𝑐 )  ↔  ( (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑏 )  ∧  (  bday  ‘ 𝑏 )  ∈  (  bday  ‘ 𝑐 ) ) ) ) | 
						
							| 16 | 1 | lrrecval2 | ⊢ ( ( 𝑎  ∈   No   ∧  𝑐  ∈   No  )  →  ( 𝑎 𝑅 𝑐  ↔  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑐 ) ) ) | 
						
							| 17 | 16 | 3adant2 | ⊢ ( ( 𝑎  ∈   No   ∧  𝑏  ∈   No   ∧  𝑐  ∈   No  )  →  ( 𝑎 𝑅 𝑐  ↔  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑐 ) ) ) | 
						
							| 18 | 15 17 | imbi12d | ⊢ ( ( 𝑎  ∈   No   ∧  𝑏  ∈   No   ∧  𝑐  ∈   No  )  →  ( ( ( 𝑎 𝑅 𝑏  ∧  𝑏 𝑅 𝑐 )  →  𝑎 𝑅 𝑐 )  ↔  ( ( (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑏 )  ∧  (  bday  ‘ 𝑏 )  ∈  (  bday  ‘ 𝑐 ) )  →  (  bday  ‘ 𝑎 )  ∈  (  bday  ‘ 𝑐 ) ) ) ) | 
						
							| 19 | 10 18 | mpbiri | ⊢ ( ( 𝑎  ∈   No   ∧  𝑏  ∈   No   ∧  𝑐  ∈   No  )  →  ( ( 𝑎 𝑅 𝑏  ∧  𝑏 𝑅 𝑐 )  →  𝑎 𝑅 𝑐 ) ) | 
						
							| 20 | 19 | adantl | ⊢ ( ( ⊤  ∧  ( 𝑎  ∈   No   ∧  𝑏  ∈   No   ∧  𝑐  ∈   No  ) )  →  ( ( 𝑎 𝑅 𝑏  ∧  𝑏 𝑅 𝑐 )  →  𝑎 𝑅 𝑐 ) ) | 
						
							| 21 | 7 20 | ispod | ⊢ ( ⊤  →  𝑅  Po   No  ) | 
						
							| 22 | 21 | mptru | ⊢ 𝑅  Po   No |