Abstract: Three or more wires are configured as a differential “skein” (FIG. 1). Symbols may use equal voltages as well as differing voltages. “Softpairs” (132 142 152) of a “skein” are discriminated in differential mode by “relational comparators” (200), exploiting hysteresis in differential comparators to detect voltage near-equality versus signed difference. Data rates up to 3 bits/transition on three wires, 6 b/tr on four wires, 9 b/tr on five wires.