[conv.qual] Avoid bouncing back and forth between subscripts and regular

scripts for T1 and T2, and add missing definition for cv^j_i and P^j_i.

Author: zygoloid

source/expressions.tex

@@ -730,7 +730,7 @@
 
 \pnum
 \indextext{type!similar|see{similar types}}%
-Two types $\tcode{T}_1$ and $\tcode{T}_2$ are \defnx{similar}{similar types} if
+Two types \tcode{T1} and \tcode{T2} are \defnx{similar}{similar types} if
 they have cv-decompositions with the same $n$
 such that corresponding $P_i$ components are either the same
 or one is ``array of $N_i$'' and the other is ``array of unknown bound of'',
@@ -752,9 +752,11 @@
 or the resulting $P^3_i$ is different from $P^1_i$ or $P^2_i$,
 then \tcode{const} is added to every $\cv{}^3_k$ for $0 < k < i$.
 \end{itemize}
-A prvalue of type $\tcode{T}_1$
-can be converted to type $\tcode{T}_2$
-if the cv-combined type of $\tcode{T}_1$ and $\tcode{T}_2$ is $\tcode{T}_2$.
+where $\cv{}^j_i$ and $P^j_i$ are the components of
+the cv-decomposition of $\tcode{T}j$.
+A prvalue of type \tcode{T1}
+can be converted to type \tcode{T2}
+if the cv-combined type of \tcode{T1} and \tcode{T2} is \tcode{T2}.
 \begin{note}
 If a program could assign a pointer of type \tcode{T**} to a pointer of
 type \tcode{const} \tcode{T**} (that is, if line \#1 below were