Inference Rules for Propositional Logic


  1. Modus Ponens or Implication-Elimination:
    A => B, A
    ---------
        B
    
  2. And-Elimination:
    A1 and A2 and ... An
    --------------------
            Ai
    
  3. And-Introduction:
      A1, A2, ... An
    --------------------
    A1 and A2 and ... An
    
  4. Or-Introduction:
           Ai
    ------------------
    A1 or A2 or ... An
    
  5. Double-Negation Elimination:
    NOT(NOT(A))
    -----------
         A
    
  6. Unit Resolution:
    A or B, NOT(B)
    ---------------
            A
    
  7. Resolution:
    A or B, NOT(B) or C
    -------------------
            A or C