[see also: condition, hypothesis, requirement
We make two standing assumptions on the maps under consideration.
By the smoothness assumption on f,......
By assumption,......
If the boundary is never hit then xt is a Feller process under reasonable continuity assumptions.
We establish our results both unconditionally and on the assumption of the Riemann Hypothesis.
We note that the assumption of GCH is made for convenience and ease of presentation.
......, contrary to assumption.
a basic <fundamental/implicit/tacit/underlying/reasonable/erroneous> assumption