inst (out[3:2], in); — the LRM pages 163–164 idiom — used to be a parse
error. bus_split.va drives a 4-bit bus with V(v[k]) = k volts and wires
it to three instances by slicing; each output is 2·V(msb) + V(lsb), so
the DC values pin the exact per-bit routing:
| Form | Connection | Expected |
|---|---|---|
| positional | p1 (o1, v[3:2]) |
8 V |
| named | p2 (.o(o2), .i(v[1:0])) |
2 V |
| width-1 onto scalar | s1 (o3, v[2:2]) |
2 V |
A part-select in behavioral code is rejected with a dedicated diagnostic
(also checked). Run: python3 verify_partselect.py (5 checks).