Whether the restaurant property in J. was business assets or private assets for direct federal tax purposes.
The property was predominantly used for business and therefore qualified as business assets; the capital gain on sale was taxable.
The decisive criterion is the current technical-economic function of the asset. The court upheld the lower court's factual findings on use, rejected the new post-sale rent argument as an inadmissible novum, and held that bookkeeping and the 50/50 allocation used for cantonal property-gain tax did not control the federal income-tax qualification under the prevalence method.