A mom and son having fun at the lake during winter.`
The mom and son are ice fishing.
They are not necessarily ice fishing.
(x)
exists p1 x1 x2 x3.(n_son(x3) & n_mom(x2) & subset_of(x3,x1) & subset_of(x2,x1) & exists x4 x5.((x1 = x4) & n_fishing(x4) & of(x4,x5) & n_ice(x5)))