Construct an NPDA to recognize $\{a^n{b}^{n+m}{c}^m$:$n,m0\}.$

Construct a $2-$PDA to recognize $\{0^m{1}^n{0}^m{1}^n$:$n,m0\}.$

Prove that the language $\{0^m{1}^n{0}^m{1}^n$:$n,m0\}!$inCFL.