Typo fix

Doc/lib/libdecimal.tex

@@ -883,7 +883,7 @@ The number system for the \module{decimal} module provides special
 values including \constant{NaN}, \constant{sNaN}, \constant{-Infinity},
 \constant{Infinity}, and two zeroes, \constant{+0} and \constant{-0}.
 
-Infinities can constructed directly with:  \code{Decimal('Infinity')}. Also,
+Infinities can be constructed directly with:  \code{Decimal('Infinity')}. Also,
 they can arise from dividing by zero when the \exception{DivisionByZero}
 signal is not trapped.  Likewise, when the \exception{Overflow} signal is not
 trapped, infinity can result from rounding beyond the limits of the largest