### What does assume(x, "real")?

I do not understand what permits the construction `assume(x, "real")`

. For instance,

```
sage: assume(x, "real")
sage: bool(x*x>0)
False
```

I would expect the answer to be `True`

.

Note that Maxima always answers `True`

for the same inequality:

```
sage: forget()
sage: bool(maxima(x*x>0))
True
```

I am not sure this is a better behaviour though.