Superscript not obeying brackets

Question

I am trying to put in superscript only what is in brackets:

(2) Let $\overline{h \circ s}(v) = h(\overline s(c)) = h(c^ {\mathfrak_{U}} )$ when $c$ is a constant. \\

(3) $\overline{h \circ s}(f_{t_1}...f_{t_2}) = h(\overline s(f_{t_1}...f_{t_2})) = h (f^{\mathfrak_{U}} (\overline s(t_1), ..., \overline s(t_2))$ when $f$ is a function.

But I keep getting this weirdness. What's going wrong?

Answer 1

\mathfrak_{U} should be \mathfrak{U}.