also removed uniqueness for dependent pair types from symbol list

symbols.tex

@@ -255,7 +255,6 @@ \chapter*{Index of symbols}
 %%%%%%%%%% U %%%%%%%%%%
 \symbolindex{$\nameless$	}{an unnamed object or variable}
 \symbolindex{$A \cup B$	}{union of subsets, \pg{union}}
-\symbolindex{$\uniq{\sm{x:A}P(x)}$}{uniqueness principle for dependent pair type $\sm{x:A}P(x)$, \pg{thm:eta-sigma}}
 \symbolindex{$\uniq{A\times B}$ }{uniqueness principle for the product $A\times B$, \pg{uniquenessproduct}}
 \symbolindex{$\uniq{\unit}$     }{uniqueness principle for $\unit$, \pg{uniquenessunit}}
 \symbolindex{$\UU$	}{universe type, \pg{sec:universes}}