The matrix's stages at an arbitrary file #
DescriptiveComplexity.Problems.Wide.DrawInstMat read at a coarse file: the
four atom runs – comparison, expansion, stage and gate block – wrapped into the
one shape the sequencer drives them through, entry one cell to the marker's
right at the Slot.val-walked presentation and exit at the next checkpoint.
Each wrapper is the clocked run of its atom with the walk-back the dispatch
owes, so each carries its atom's budget plus one step.