your Boolean function in HDL And.hdl: /** * And gate: * out = 1 if (a == 1 and b == 1) * 0 otherwise */ CHIP And { IN a, b; OUT out; PARTS: Nand(a=a, b=b, out=nandAB); Not(in=nandAB, out=out); } Mystery.hdl CHIP Mystery { IN a, b, c, d; OUT out; PARTS: } Not.hdl /** * Not gate: * out = not in */ CHIP Not { IN in; OUT out; PARTS: // Put your code here: Nand(a=in, b=in, out=out); } Or.hdl /** * Or gate: out = 1 if {a==1 or b==1}, 0 otherwise *

code your Boolean function in HDL

And.hdl:

/** * And gate: * out = 1 if (a == 1 and b == 1) * 0 otherwise */ CHIP And { IN a, b; OUT out; PARTS: Nand(a=a, b=b, out=nandAB); Not(in=nandAB, out=out); }

Mystery.hdl

CHIP Mystery { IN a, b, c, d; OUT out; PARTS: }

Not.hdl

/** * Not gate: * out = not in */ CHIP Not { IN in; OUT out; PARTS: // Put your code here: Nand(a=in, b=in, out=out); }

Or.hdl

/** * Or gate: out = 1 if {a==1 or b==1}, 0 otherwise */ CHIP Or { IN a, b; OUT out; PARTS: Not (in=a, out=nota); Not (in=b, out=notb); Nand (a=nota, b=notb, out=out); }