I posted the question here because it seemed to me the least unrelated to the question.

Of the following integral I am interested only in the real part. How can I force to consider a>x>0?

Or, alternatively, how can I select only the second one between the two results?

```
julia> using SymPy
julia> @syms x y a b
(x, y, a, b)
julia> integrate(sqrt(a^2-x^2),x)
⎧ 2 ⎛x⎞
⎪ ⅈ⋅a ⋅acosh⎜─⎟ 3 │ 2│
⎪ ⎝a⎠ ⅈ⋅a⋅x ⅈ⋅x │x │
⎪- ───────────── - ───────────────── + ─────────────────── for │──│ > 1
⎪ 2 _________ _________ │ 2│
⎪ ╱ 2 ╱ 2 │a │
⎪ ╱ x ╱ x
⎪ 2⋅ ╱ -1 + ── 2⋅a⋅ ╱ -1 + ──
⎪ ╱ 2 ╱ 2
⎨ ╲╱ a ╲╱ a
⎪
⎪ ________
⎪ ╱ 2
⎪ ╱ x
⎪ 2 ⎛x⎞ a⋅x⋅ ╱ 1 - ──
⎪ a ⋅asin⎜─⎟ ╱ 2
⎪ ⎝a⎠ ╲╱ a
⎪ ────────── + ────────────────── otherwise
⎩ 2 2
```