module and_1 (y,a,b);
 input a, b;
 output y;

    and x1 (y,a,b);
        
        if ( a == b)
         y = 1'b0;
        else 
         y = 1'bx; 

        if ( a == 1 )
         y = 1'b1;
        else 
         y = 1'b0; 


  
endmodule

##</code><code>##

module or_1 (y,a,b);
 input a, b;
 output y;

    or x1 (y,a,b);
        
        if ( a == b)
         y = 1'b0;
       else 
         y = 1'bx; 

        if ( a == 0 )
         y = 1'b0;
        else 
         y = 1'b1; 

 
endmodule

##</code><code>##

module and_1 (y,a,b);
 input a, b;
 output y;

    and x1 (y,a,b);
        
        if ( a == b)
         y = 1'bx;
        else 
         y = 1'b0; 

        if ( a == 0 )
         y = 1'bx;
        else 
         y = 1'b1; 


  
endmodule
module or_1 (y,a,b);
 input a, b;
 output y;

    or x1 (y,a,b);
        
        if ( a == b)
         y = 1'b1;
        else 
         y = 1'b0; 

        if ( a == 0 )
         y = 1'bz;
        else 
         y = 1'bx; 

 
endmodule


##</code><code>##

module and_1 (y,a,b); //not changing anything
 input a, b;
 output y;

    nand x1 (y,a,b); //and changed to nand
        
        if ( a == b) // searching for "if ( a == b)"
         y = 1'bx;  // replaced condition "y = 1'b0;" in FILE1 with "y = 1'bx;" from FILE2
        else 
         y = 1'b0; // similarly from the upper

        if ( a == 1 )
         y = 1'bx;
        else 
         y = 1'b1; 


  
endmodule

module or_1 (y,a,b);
 input a, b;
 output y;

    xor x1 (y,a,b);
        
        if ( a == b)
         y = 1'b1;
        else 
         y = 1'b0; 

        if ( a == 0 )
         y = 1'bz;
        else 
         y = 1'bx; 

 
endmodule