$6\mathrm{.}2$

Using the natural deduction rules, give a formal proof of:

SameSize Large$($c$)vv$ Small$($c$))$

from the premises:

Small$($a$)$ Small$($b$)$

Small$($b$)($SameSize$($b$,$ c$)$ Small$($c$))$

$$Small Large $(c)$