// Reversed process: is there an adjacent obstacle,
// and a grasshopper next in the same line?
for (const step of V.steps[V.ROOK].concat(V.steps[V.BISHOP])) {
// Reversed process: is there an adjacent obstacle,
// and a grasshopper next in the same line?
for (const step of V.steps[V.ROOK].concat(V.steps[V.BISHOP])) {