$3$ Red$-$B$^($lack Trees

Code for the inference rules and definitions is below so you can have examples of how to typeset these.

Trees $,T,$::$=$ Leaf $|BNode(T,T)|RNode(T,T)$

Colors $c,$::$=$ Black$|$Red

Task $3.$ Prove by rule induction that for any tree T$,$ color c in $\{$Red$,$Black$\}$ and n $>=1,$ if T isTree c n$,$ then Nodes$($T$)>=2$n$1.$