P3914R0: Re NB US 160-260 (C++26 CD)

Fixes NB US 160-260 (C++26 CD).

Author: eisenwave

source/algorithms.tex

@@ -7839,9 +7839,11 @@
 \pnum
 Let \tcode{pred} be \tcode{equal_to\{\}}
 for the overloads with no parameter \tcode{pred}, and
-let $E$ be
+let $E(\tcode{i})$ be
 \begin{itemize}
 \setlength{\emergencystretch}{1em}
+\item
+  \tcode{false} if \tcode{i} is equal to \tcode{first}; otherwise
 \item
   \tcode{bool(pred(*(i - 1), *i))}
   for the overloads in namespace \tcode{std};
@@ -7859,10 +7861,9 @@
 
 \pnum
 \effects
-For a nonempty range, eliminates all but the first element
-from every consecutive group of equivalent elements referred to
+Eliminates all elements referred to
 by the iterator \tcode{i} in the range \range{first + 1}{last}
-for which $E$ is \tcode{true}.
+for which $E(\tcode{i})$ is \tcode{true}.
 
 \pnum
 \returns
@@ -7942,6 +7943,8 @@
 let $E(\tcode{i})$ be
 \begin{itemize}
 \setlength{\emergencystretch}{1em}
+\item
+  \tcode{false} if \tcode{i} is equal to \tcode{first}; otherwise
 \item
   \tcode{bool(pred(*i, *(i - 1)))}
   for the overloads in namespace \tcode{std};
@@ -7954,13 +7957,13 @@
 Let:
 \begin{itemize}
 \item
-  $M$ be the number of iterators \tcode{i} in the range \range{first + 1}{last}
+  $M$ be the number of iterators \tcode{i} in the range \range{first}{last}
   for which $E(\tcode{i})$ is \tcode{false};
 \item
-  \tcode{result_last} be \tcode{result + $M$ + 1}
+  \tcode{result_last} be \tcode{result + $M$}
   for the overloads with no parameter \tcode{result_last} or \tcode{result_r};
 \item
-  $N$ be $\min(M + 1, \ \tcode{result_last - result})$.
+  $N$ be $\min(M, \ \tcode{result_last - result})$.
 \end{itemize}
 
 \pnum
@@ -8006,9 +8009,9 @@
 
 \pnum
 \effects
-Copies only the first element from $N$ consecutive groups of equivalent elements
-referred to by the iterator \tcode{i} in the range \range{first + 1}{last}
-for which $E(\tcode{i})$ holds
+Copies only the first $N$ elements
+referred to by the iterator \tcode{i} in the range \range{first}{last}
+for which $E(\tcode{i})$ is \tcode{true}
 into the range \range{result}{result + $N$}.
 
 \pnum
@@ -8020,13 +8023,13 @@
 \item
   \tcode{\{last, result + $N$\}}
   for the overloads in namespace \tcode{ranges},
-  if $N$ is equal to $M + 1$.
+  if $N$ is equal to $M$.
 \item
   Otherwise, \tcode{\{j, result_last\}}
   for the overloads in namespace \tcode{ranges},
-  where \tcode{j} is the iterator in \range{first + 1}{last}
+  where \tcode{j} is the iterator in \range{first}{last}
   for which $E(\tcode{j})$ is \tcode{false}
-  and there are exactly $N - 1$ iterators \tcode{i} in \range{first + 1}{j}
+  and there are exactly $N$ iterators \tcode{i} in \range{first}{j}
   for which $E(\tcode{i})$ is \tcode{false}.
 \end{itemize}