theorem reseq0 (A F: set): $ Dom F i^i A == 0 <-> F |` A == 0 $;
    
      
        | Step | Hyp | Ref | Expression | 
        
          | 1 | 
           | 
          bitr4 | 
          (Dom F i^i A == 0 <-> Dom F C_ Compl A) -> (F |` A == 0 <-> Dom F C_ Compl A) -> (Dom F i^i A == 0 <-> F |` A == 0)  | 
        
        
          | 2 | 
           | 
          ineq0 | 
          Dom F i^i A == 0 <-> Dom F C_ Compl A  | 
        
        
          | 3 | 
          1, 2 | 
          ax_mp | 
          (F |` A == 0 <-> Dom F C_ Compl A) -> (Dom F i^i A == 0 <-> F |` A == 0)  | 
        
        
          | 4 | 
           | 
          bitr4 | 
          (F |` A == 0 <-> F C_ Compl (Xp A _V)) -> (Dom F C_ Compl A <-> F C_ Compl (Xp A _V)) -> (F |` A == 0 <-> Dom F C_ Compl A)  | 
        
        
          | 5 | 
           | 
          ineq0 | 
          F i^i Xp A _V == 0 <-> F C_ Compl (Xp A _V)  | 
        
        
          | 6 | 
          5 | 
          conv res | 
          F |` A == 0 <-> F C_ Compl (Xp A _V)  | 
        
        
          | 7 | 
          4, 6 | 
          ax_mp | 
          (Dom F C_ Compl A <-> F C_ Compl (Xp A _V)) -> (F |` A == 0 <-> Dom F C_ Compl A)  | 
        
        
          | 8 | 
           | 
          bitr4 | 
          (Dom F C_ Compl A <-> F C_ Xp (Compl A) _V) -> (F C_ Compl (Xp A _V) <-> F C_ Xp (Compl A) _V) -> (Dom F C_ Compl A <-> F C_ Compl (Xp A _V))  | 
        
        
          | 9 | 
           | 
          ssdm | 
          Dom F C_ Compl A <-> F C_ Xp (Compl A) _V  | 
        
        
          | 10 | 
          8, 9 | 
          ax_mp | 
          (F C_ Compl (Xp A _V) <-> F C_ Xp (Compl A) _V) -> (Dom F C_ Compl A <-> F C_ Compl (Xp A _V))  | 
        
        
          | 11 | 
           | 
          sseq2 | 
          Compl (Xp A _V) == Xp (Compl A) _V -> (F C_ Compl (Xp A _V) <-> F C_ Xp (Compl A) _V)  | 
        
        
          | 12 | 
           | 
          cplxpv2 | 
          Compl (Xp A _V) == Xp (Compl A) _V  | 
        
        
          | 13 | 
          11, 12 | 
          ax_mp | 
          F C_ Compl (Xp A _V) <-> F C_ Xp (Compl A) _V  | 
        
        
          | 14 | 
          10, 13 | 
          ax_mp | 
          Dom F C_ Compl A <-> F C_ Compl (Xp A _V)  | 
        
        
          | 15 | 
          7, 14 | 
          ax_mp | 
          F |` A == 0 <-> Dom F C_ Compl A  | 
        
        
          | 16 | 
          3, 15 | 
          ax_mp | 
          Dom F i^i A == 0 <-> F |` A == 0  | 
        
      
    
    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)