| Step | Hyp | Ref | Expression | 
						
							| 1 |  | nn0opthlem1.1 |  |-  A e. NN0 | 
						
							| 2 |  | nn0opthlem1.2 |  |-  C e. NN0 | 
						
							| 3 |  | 1nn0 |  |-  1 e. NN0 | 
						
							| 4 | 1 3 | nn0addcli |  |-  ( A + 1 ) e. NN0 | 
						
							| 5 | 4 2 | nn0le2msqi |  |-  ( ( A + 1 ) <_ C <-> ( ( A + 1 ) x. ( A + 1 ) ) <_ ( C x. C ) ) | 
						
							| 6 |  | nn0ltp1le |  |-  ( ( A e. NN0 /\ C e. NN0 ) -> ( A < C <-> ( A + 1 ) <_ C ) ) | 
						
							| 7 | 1 2 6 | mp2an |  |-  ( A < C <-> ( A + 1 ) <_ C ) | 
						
							| 8 | 1 1 | nn0mulcli |  |-  ( A x. A ) e. NN0 | 
						
							| 9 |  | 2nn0 |  |-  2 e. NN0 | 
						
							| 10 | 9 1 | nn0mulcli |  |-  ( 2 x. A ) e. NN0 | 
						
							| 11 | 8 10 | nn0addcli |  |-  ( ( A x. A ) + ( 2 x. A ) ) e. NN0 | 
						
							| 12 | 2 2 | nn0mulcli |  |-  ( C x. C ) e. NN0 | 
						
							| 13 |  | nn0ltp1le |  |-  ( ( ( ( A x. A ) + ( 2 x. A ) ) e. NN0 /\ ( C x. C ) e. NN0 ) -> ( ( ( A x. A ) + ( 2 x. A ) ) < ( C x. C ) <-> ( ( ( A x. A ) + ( 2 x. A ) ) + 1 ) <_ ( C x. C ) ) ) | 
						
							| 14 | 11 12 13 | mp2an |  |-  ( ( ( A x. A ) + ( 2 x. A ) ) < ( C x. C ) <-> ( ( ( A x. A ) + ( 2 x. A ) ) + 1 ) <_ ( C x. C ) ) | 
						
							| 15 | 1 | nn0cni |  |-  A e. CC | 
						
							| 16 |  | ax-1cn |  |-  1 e. CC | 
						
							| 17 | 15 16 | binom2i |  |-  ( ( A + 1 ) ^ 2 ) = ( ( ( A ^ 2 ) + ( 2 x. ( A x. 1 ) ) ) + ( 1 ^ 2 ) ) | 
						
							| 18 | 15 16 | addcli |  |-  ( A + 1 ) e. CC | 
						
							| 19 | 18 | sqvali |  |-  ( ( A + 1 ) ^ 2 ) = ( ( A + 1 ) x. ( A + 1 ) ) | 
						
							| 20 | 15 | sqvali |  |-  ( A ^ 2 ) = ( A x. A ) | 
						
							| 21 | 20 | oveq1i |  |-  ( ( A ^ 2 ) + ( 2 x. ( A x. 1 ) ) ) = ( ( A x. A ) + ( 2 x. ( A x. 1 ) ) ) | 
						
							| 22 | 16 | sqvali |  |-  ( 1 ^ 2 ) = ( 1 x. 1 ) | 
						
							| 23 | 21 22 | oveq12i |  |-  ( ( ( A ^ 2 ) + ( 2 x. ( A x. 1 ) ) ) + ( 1 ^ 2 ) ) = ( ( ( A x. A ) + ( 2 x. ( A x. 1 ) ) ) + ( 1 x. 1 ) ) | 
						
							| 24 | 17 19 23 | 3eqtr3i |  |-  ( ( A + 1 ) x. ( A + 1 ) ) = ( ( ( A x. A ) + ( 2 x. ( A x. 1 ) ) ) + ( 1 x. 1 ) ) | 
						
							| 25 | 15 | mulridi |  |-  ( A x. 1 ) = A | 
						
							| 26 | 25 | oveq2i |  |-  ( 2 x. ( A x. 1 ) ) = ( 2 x. A ) | 
						
							| 27 | 26 | oveq2i |  |-  ( ( A x. A ) + ( 2 x. ( A x. 1 ) ) ) = ( ( A x. A ) + ( 2 x. A ) ) | 
						
							| 28 | 16 | mulridi |  |-  ( 1 x. 1 ) = 1 | 
						
							| 29 | 27 28 | oveq12i |  |-  ( ( ( A x. A ) + ( 2 x. ( A x. 1 ) ) ) + ( 1 x. 1 ) ) = ( ( ( A x. A ) + ( 2 x. A ) ) + 1 ) | 
						
							| 30 | 24 29 | eqtri |  |-  ( ( A + 1 ) x. ( A + 1 ) ) = ( ( ( A x. A ) + ( 2 x. A ) ) + 1 ) | 
						
							| 31 | 30 | breq1i |  |-  ( ( ( A + 1 ) x. ( A + 1 ) ) <_ ( C x. C ) <-> ( ( ( A x. A ) + ( 2 x. A ) ) + 1 ) <_ ( C x. C ) ) | 
						
							| 32 | 14 31 | bitr4i |  |-  ( ( ( A x. A ) + ( 2 x. A ) ) < ( C x. C ) <-> ( ( A + 1 ) x. ( A + 1 ) ) <_ ( C x. C ) ) | 
						
							| 33 | 5 7 32 | 3bitr4i |  |-  ( A < C <-> ( ( A x. A ) + ( 2 x. A ) ) < ( C x. C ) ) |