Yes!You can't have AND gate using XOR gate! You can only
getbuffer or inverter!
To be an universal gate a gate needs to satisfy both the
following conditions!1. You should be able to get inverter using
the gate.2. You should be able to block the input.
Here by 2 what i means is this....Take a 2 input NAND gate 1. is
satisfied if you connect one input to '1' o/p will be inversion of
input!2. is satisfied if you connect one input to '0' o/p will be
'1' other input wonthave any effect on o/p. i.e. other input gets
blocked!
Only a MUX, NAND and NOR gates satisfy both the above conditions
and areUniversal gates!XOR satisfies only 1st condition!
