; homework 13 
; using de morgans law 
; no XOR instruction in lc3 assemble lang only AND and NOT 
; A XOR B = (A NAND (A NAND B)) NAND (B NAND (A NAND B))
; A NAND B = NOT(A AND B) = #R3

AND   R3,R1,R2     
NOT   R3,R3

AND   R1,,R1,R3     
NOT   R1,R1

AND   R2,R2,R3     
NOT   R2,R2

AND   R0,R1,R2     
NOT   R0,R0