Profit is a function of accounting.
But positive account balances infer positive cash flow. See theorems 1 and 2 in the HTML file attached below. Lines of credit with the entrepreneur's suppliers and banks are conceptually included in his account balances enabling increasing disbursement. The entrepreneur's operation is sustainable so long as his account balances are increasing, regardless of his firm's putative profit. There are things that we do not conclude by logic but accept as true because we see or observe them.