The phrase "assumption would have" is correct and usable in written English.
It can be used when discussing hypothetical situations or conditions that rely on a certain assumption being true.
Example: "If the assumption would have been accurate, the results of the experiment would have been different."
Alternatives: "assumption might have" or "assumption could have".
As events proved, that assumption would have been wrong.
Instead, they say, the assumption would have been that it would be Bill Wood.
The easy assumption would have been that the someone was Alejandro, but I understood instinctively that this wasn't the case.
No one knows why, although a reasonable assumption would have to be that they were too fat and ugly.
Is it credible that Steenkamp didn't guess Pistorius had his gun, since her assumption would have been that he'd come from the bedroom?
A loftier assumption would have it that the bleak events of recent history have inspired a collective will to go back and reverse course.
The discipline of systematically identifying key assumptions would have highlighted the business plan's vulnerabilities.
Under the new rules, those assumptions would have to be revised every three months, leading to changes in the book value of the policies.
They suddenly collapsed the pressure inside the bacteria, but instead of causing the cell wall to massively shrink, as prevailing assumptions would have predicted, they found that the outer membrane was strong enough to almost entirely maintain E. coli's cucumber shape.
Prof Regan says a series of assumptions would have been made in order to ascertain how much Po-210 may or may not have been in Mr Arafat's body at the time of his death.
For the argument to be plausible today, such assumptions would have to be defended, or else the argument reformulated in a way that frees it from its original metaphysical home.
