Order affirmed, without costs. The issue on this record whether claimant was a five-day worker or a six-day worker was a question of ultimate fact although the underlying facts were undisputed, and, because there was substantial evidence supporting the board’s finding that he was a five-day worker, its finding is invulnerable.

Concur: Chief Judge Breitel and Judges Jasen, Gabrielli, Jones, Wachtler, Babin and Stevens.