>>8175
I don't think so. From my dictionary, postulate means: An axiom (truth and not an assumption) from mathematics's point of view.
How about just make a "word-word" (hyphenated) rather than ostensible since it's just informal.
I'll just copy pasta the rest of the meaning of postulate:
pos·tu·late (pŏs′chə-lāt′)
tr.v. pos·tu·lat·ed, pos·tu·lat·ing, pos·tu·lates
1. To assume or assert the truth, reality, or necessity of, especially as a basis of an argument: "We can see individuals, but we can't see providence; we have to postulate it" (Aldous Huxley).
2. To propose as a hypothesis or explanation: Researchers now postulate that the disease is caused by a virus.
3. To assume as a premise or axiom; take for granted.
4. Archaic To make claim for; demand.
n. (pŏs′chə-lĭt, -lāt′)
1. Something assumed without proof as being self-evident or generally accepted, especially when used as a basis for an argument: "the postulate that there is little moral difference between the superpowers" (Henry A. Kissinger).
2. A fundamental element; a basic principle.
3. Mathematics An axiom.
4. Archaic A requirement; a prerequisite.