00100 LE1(X1 X2) ∨ LE1(X2 X1); 00200 (LE1(X1 X2) ∧ LE1(X2 X1))→ E(X1 X2); 00300 (LE1(X1 X2) ∧ LE1(X2 X3)) → LE1(X1 X3); 00400 LE1(X1 ADD1(X1)); 00500 ¬E(X1 ADD1(X1)); 00600 LE1(X2 X1) ∨ LE1(ADD1(X1) X2); 00700 LE1(X1 X1); 00800 ;