* doc/tl/tl.tex: Typos.

doc/tl/tl.tex

@@ -1120,7 +1120,7 @@ methods \texttt{is\_syntactic\_safety()},
 page~\pageref{property-methods}).
 
 The symbols $\varphi_G$, $\varphi_S$, $\varphi_O$, $\varphi_P$,
-$\varphi_R$ denot any formula belonging respectively to the
+$\varphi_R$ denote any formula belonging respectively to the
 Guarantee, Safety, Obligation, Persistence, or Recurrence classes.
 $\varphi_F$ denotes a finite LTL formula (the unnamed class at the
 intersection of Safety and Guarantee formul\ae{} on
@@ -1697,7 +1697,7 @@ f)\implies(\pi\VDash g)$.
 The recursive rules for syntactic implication are rules are described
 in table~\ref{tab:syntimpl}, in which $\simp$ denotes the syntactic
 implication, $f$, $f_1$, $f_2$, $g$, $g_1$ and $g_2$ denote any PSL
-formula in negative normal form, and $f_U$ and $g_E$ denot a
+formula in negative normal form, and $f_U$ and $g_E$ denote a
 purely universal formula and a pure eventuality.
 
 The form on the left of the table syntactically implies the form on