COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	\input basic
C00004 ENDMK
C⊗;
\input basic
\hsize 360pt
\def\longright{\mathrel{{-}\!{-}\!{→}}}
\def\overarrow#1{\mathrel{\vjust to 7.5pt{\vskip 0pt minus 1000pt
\baselineskip12pt\hjust to 26.777pt{\ctr{$#1$}}\vskip-5pt
\hjust{$\longright$}}}}
\def\\#1{\hjust to 5pt{\ctr{$#1$}}}
\def\leftofarrow#1{\hjust to 0pt{\hskip 0pt minus 10000pt $#1\;$}\!
\vcenter{\baselineskip12pt\\| \vskip-4pt \\\down}}
Frank Peterson's formula is
$$\lineskip 0pt\def\strut{\lower 7.5pt\vjust to 20pt{}}
\vcenter{\halign{\strut$\rt{#}\null$⊗$\ctr{#}$⊗$\ctr{\null#\null}$⊗\!
$\ctr{#}$⊗$\ctr{\null#\null}$⊗\!
$\ctr{#}$⊗$\ctr{\null#\null}$⊗\!
$\ctr{#}$⊗$\lft{\null#}$\cr
\cdots\longright⊗H↓n(A;G)⊗\overarrow{i↓\ast}⊗H↓n(X;G)⊗\overarrow{j↓\ast}⊗\!
H↓n(X,A;G)⊗\overarrow{∂}⊗H↓{n-1}(A;G)⊗\longright\cdots\cr
⊗\leftofarrow{(f|A)↓\ast}⊗⊗\leftofarrow{f↓\ast}⊗⊗\leftofarrow{f↓\ast}⊗⊗\leftofarrow
{(f|A)↓\ast}\cr
\cdots\longright⊗H↓n(B;G)⊗\overarrow{i↓\ast}⊗H↓n(Y;G)⊗\overarrow{j↓\ast}⊗\!
H↓n(Y,B;G)⊗\overarrow{∂}⊗H↓{n-1}(B;G)⊗\longright\cdots\cr}}$$
(maybe).

\vfill\end