| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rrx2plord.o | ⊢ 𝑂  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  𝑅  ∧  𝑦  ∈  𝑅 )  ∧  ( ( 𝑥 ‘ 1 )  <  ( 𝑦 ‘ 1 )  ∨  ( ( 𝑥 ‘ 1 )  =  ( 𝑦 ‘ 1 )  ∧  ( 𝑥 ‘ 2 )  <  ( 𝑦 ‘ 2 ) ) ) ) } | 
						
							| 2 |  | rrx2plord2.r | ⊢ 𝑅  =  ( ℝ  ↑m  { 1 ,  2 } ) | 
						
							| 3 |  | ltso | ⊢  <   Or  ℝ | 
						
							| 4 |  | eqid | ⊢ { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) }  =  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) } | 
						
							| 5 | 4 | soxp | ⊢ ( (  <   Or  ℝ  ∧   <   Or  ℝ )  →  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) }  Or  ( ℝ  ×  ℝ ) ) | 
						
							| 6 | 3 3 5 | mp2an | ⊢ { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) }  Or  ( ℝ  ×  ℝ ) | 
						
							| 7 |  | eqid | ⊢ ( 𝑥  ∈  ℝ ,  𝑦  ∈  ℝ  ↦  { 〈 1 ,  𝑥 〉 ,  〈 2 ,  𝑦 〉 } )  =  ( 𝑥  ∈  ℝ ,  𝑦  ∈  ℝ  ↦  { 〈 1 ,  𝑥 〉 ,  〈 2 ,  𝑦 〉 } ) | 
						
							| 8 | 1 2 7 4 | rrx2plordisom | ⊢ ( 𝑥  ∈  ℝ ,  𝑦  ∈  ℝ  ↦  { 〈 1 ,  𝑥 〉 ,  〈 2 ,  𝑦 〉 } )  Isom  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) } ,  𝑂 ( ( ℝ  ×  ℝ ) ,  𝑅 ) | 
						
							| 9 |  | isoso | ⊢ ( ( 𝑥  ∈  ℝ ,  𝑦  ∈  ℝ  ↦  { 〈 1 ,  𝑥 〉 ,  〈 2 ,  𝑦 〉 } )  Isom  { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) } ,  𝑂 ( ( ℝ  ×  ℝ ) ,  𝑅 )  →  ( { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) }  Or  ( ℝ  ×  ℝ )  ↔  𝑂  Or  𝑅 ) ) | 
						
							| 10 | 8 9 | ax-mp | ⊢ ( { 〈 𝑥 ,  𝑦 〉  ∣  ( ( 𝑥  ∈  ( ℝ  ×  ℝ )  ∧  𝑦  ∈  ( ℝ  ×  ℝ ) )  ∧  ( ( 1st  ‘ 𝑥 )  <  ( 1st  ‘ 𝑦 )  ∨  ( ( 1st  ‘ 𝑥 )  =  ( 1st  ‘ 𝑦 )  ∧  ( 2nd  ‘ 𝑥 )  <  ( 2nd  ‘ 𝑦 ) ) ) ) }  Or  ( ℝ  ×  ℝ )  ↔  𝑂  Or  𝑅 ) | 
						
							| 11 | 6 10 | mpbi | ⊢ 𝑂  Or  𝑅 |