Order unanimously modified in accordance with memorandum and, as modified, affirmed, without costs. Memorandum: The subcontractor, Estey, has been awarded summary judgment against the general contractor, Smith, and the general contractor has been awarded summary judgment against the owner, Syracuse University, for costs involved in supplying shelves for the second side of double faced bookstack units. However, the specifications as to shelving incorporated in the contracts between the parties were ambiguous on their face and, to resolve that ambiguity, extrinsic evidence must be received which there will be a choice of reasonable inferences to be made by a jury ( Hartford Acc. Ind. Co. v. Wesolowski, 33 N.Y.2d 169). The order should be modified to strike out the awards of summary judgment and the direction for assessment of damages as to the claim for shelving; as to that item summary judgment should be denied to all parties. Insofar as the order granted summary judgment as to the subcontractor's claims for extra costs for supplying card catalog trays with rods and for bookstack uprights, in one instance in favor of the subcontractor and in the other instance against it, the order should be affirmed.