E = size 3 by 3 arity-2 Expression of double:
[ 1 2 9 ]
[ 4 6 5 ]
[ 7 3 8 ]

E > 4.0 = size 3 by 3 arity-2 Expression of bool:
[ 0 0 1 ]
[ 0 1 1 ]
[ 1 0 1 ]

Matrix::evaluate(pow(E,2)) = size 3 by 3 Matrix of double:
[ 1 4 81 ]
[ 16 36 25 ]
[ 49 9 64 ]

