theorem dvdcop (G: wff) (a b d: nat):
  $ G -> coprime a b $ >
  $ G -> d || a $ >
  $ G -> d || b $ >
  $ G -> d = 1 $;
    
      
        | Step | Hyp | Ref | Expression | 
        
          | 1 | 
           | 
          dvd12 | 
          d || 1 <-> d = 1  | 
        
        
          | 2 | 
           | 
          hyp h1 | 
          G -> coprime a b  | 
        
        
          | 3 | 
          2 | 
          conv coprime | 
          G -> gcd a b = 1  | 
        
        
          | 4 | 
          3 | 
          dvdeq2d | 
          G -> (d || gcd a b <-> d || 1)  | 
        
        
          | 5 | 
           | 
          dvdgcd | 
          d || gcd a b <-> d || a /\ d || b  | 
        
        
          | 6 | 
           | 
          hyp h2 | 
          G -> d || a  | 
        
        
          | 7 | 
           | 
          hyp h3 | 
          G -> d || b  | 
        
        
          | 8 | 
          6, 7 | 
          iand | 
          G -> d || a /\ d || b  | 
        
        
          | 9 | 
          5, 8 | 
          sylibr | 
          G -> d || gcd a b  | 
        
        
          | 10 | 
          4, 9 | 
          mpbid | 
          G -> d || 1  | 
        
        
          | 11 | 
          1, 10 | 
          sylib | 
          G -> d = 1  | 
        
      
    
    Axiom use
    axs_prop_calc
     (ax_1,
      ax_2,
      ax_3,
      ax_mp,
      itru),
    
axs_pred_calc
     (ax_gen,
      ax_4,
      ax_5,
      ax_6,
      ax_7,
      ax_10,
      ax_11,
      ax_12),
    
axs_set
     (elab,
      ax_8),
    
axs_the
     (theid,
      the0),
    
axs_peano
     (peano1,
      peano2,
      peano5,
      addeq,
      muleq,
      add0,
      addS,
      mul0,
      mulS)