命題論理の証明パターン

\require{color}
\newcommand{\hyp}{\mbox{-}}%
\newcommand{\To}{\Rightarrow}%
\newcommand{\F}[1]{ \langle\![{#1}]\!\rangle }%
\newcommand{\As}{\;::\;}%

連言導入パターン


\langle \hyp, \hyp\rangle_{A,B,C} : {\bf ND}(A, B)\times{\bf ND}(A, C)\to {\bf ND}(A, B\land C) \mbox{ in }{\bf Set}\\
\langle F, G\rangle := copy ; (F\otimes G) ; \F{\land\hyp cons}\\
\xymatrix{
 {}
 &{}\ar[d]_-A
 &{}
\\
 {\textcolor{green}{\land}} %2,1
 &*{\bullet}\ar[dl] \ar[dr]
 &{\:\:\:\:} %2,3
\\
 *[F]{F} \ar[dr]_-B
 &{}
 &*[F]{G} \ar[dl]^-C
\\
 {}
 &*{\blacktriangledown} \ar[d]_-{B\land C}
 &{\:\:\:\:} %4,3
\\
 {}
 &{}
 &{}
\save
 "2,1" . "4,3" *[F.]\frm{}
}

選言消去パターン


[ \hyp, \hyp]_{A,B,C} : {\bf ND}(A, C)\times{\bf ND}(B, C)\to {\bf ND}(A\lor B, C) \mbox{ in }{\bf Set}\\
[ F, G] := \F{\lor\hyp decons} ; (F\oplus G) ; merge\\
\xymatrix{
 {}
 &{}\ar[d]_-{A\lor B}
 &{}
\\
 {\textcolor{green}{\lor}} %2,1
 &*{\blacktriangle}\ar[dl]_-A  \ar[dr]^-B
 &{\:\:\:\:} %2,3
\\
 *[F]{F} \ar[dr]_-C
 &{}
 &*[F]{G} \ar[dl]^-C
\\
 {}
 &*{\bullet} \ar[d]_-{C}
 &{\:\:\:\:} %4,3
\\
 {}
 &{}
 &{}
\save
 "2,1" . "4,3" *[F.]\frm{}
}

選言消去パターン 2


(\hyp;[ \hyp, \hyp])_{X,A,B,C} :{\bf ND}(X, A\lor B)\times {\bf ND}(A, C)\times{\bf ND}(B, C)\to {\bf ND}(X, C) \mbox{ in }{\bf Set}\\
H;[ F, G] := H;(\F{\lor\hyp decons} ; (F\oplus G) ; merge)\\
\xymatrix{
 {}
 &{}\ar[d]_-X
 &{}
\\
 {}
 &*[F]{H} \ar[d]_-{A\lor B}
 &{}
\\
 {\textcolor{green}{\lor}} %3,1
 &*{\blacktriangle}\ar[dl]_-A  \ar[dr]^-B
 &{\:\:\:\:} %3,3
\\
 *[F]{F} \ar[dr]_-C
 &{}
 &*[F]{G} \ar[dl]^-C
\\
 {}
 &*{\bullet} \ar[d]_-{C}
 &{\:\:\:\:} %5,3
\\
 {}
 &{}
 &{}
\save
 "3,1" . "5,3" *[F.]\frm{}
}