// declare the total evaluation result
TArray R;

// first and second term share a common intermediate (A*B)
// evaluate it as part of the first term evaluation

TArray I1;
I1("a1,x2") = A("a1,x1") * B("x1,x2");
R("a1,a2")  = I1("a1,x2") * C("x2,b1");
// done evaluating first term

// reuse the intermediate from first term evaluation
R("a1,a2") += I1("a1,y2") * D("y2,b1");
// done evaluating second term

// third term shares no intermediates
// no need to split up the evaluation like for the first term
R("a1,b1") += (C("a1,x1") * D("x1,x2")) * E("x2,b1");
// done evaluating third term