Answer
\[c\ \vartriangle \ \left[ c\ \square \ \left( c\ \vartriangle \ c \right) \right]\]is \[c\].
Work Step by Step
Find \[c\ \vartriangle \ \left[ c\ \square \ \left( c\ \vartriangle \ c \right) \right]\]as,
\[\begin{align}
& c\ \vartriangle \ \left[ c\ \square \ \left( c\ \vartriangle \ c \right) \right]=c\ \vartriangle \ \left( c\ \square \ e \right) \\
& =c\ \vartriangle \ b \\
& =c
\end{align}\]
Hence, the value of \[c\ \vartriangle \ \left[ c\ \square \ \left( c\ \vartriangle \ c \right) \right]\]is \[c\].
