# HG changeset patch # User Madarasi Peter # Date 1480114051 -3600 # Node ID 196396ea94b519f2990cd1ad7807e67b86771fee # Parent b45bac51110897e7d8593f596ccf88ae35f284f0 Vf2's consistency and cutting rules part shortened diff -r b45bac511108 -r 196396ea94b5 damecco.tex --- a/damecco.tex Thu Nov 24 22:09:36 2016 +0100 +++ b/damecco.tex Fri Nov 25 23:47:31 2016 +0100 @@ -570,22 +570,21 @@ \] \subsection{Consistency} -This section defines the consistency functions for the different -problem types mentioned in Section~\ref{sec:CommProb}. +Suppose $p=(u,v)$, where $u\in V_{small}$ and $v\in V_{large}$, $s$ is +a state of the matching procedure, $M(s)$ is consistent mapping by +$PT$ and $lab(u)=lab(v)$. $Cons_{PT}(p,M(s))$ checks whether +including pair $p$ into $M(s)$ leads to a consistent mapping by $PT$. + +For example, the consistency function of induced subgraph isomorphism is as follows. \begin{notation} Let $\mathbf{\Gamma_{small} (u)}:=\{\tilde{u}\in V_{small} : (u,\tilde{u})\in E_{small}\}$\\ Let $\mathbf{\Gamma_{large} (v)}:=\{\tilde{v}\in V_{large} : (v,\tilde{v})\in E_{large}\}$ \end{notation} -Suppose $p=(u,v)$, where $u\in V_{small}$ and $v\in V_{large}$, $s$ is -a state of the matching procedure, $M(s)$ is consistent mapping by -$PT$ and $lab(u)=lab(v)$. $Cons_{PT}(p,M(s))$ checks whether -including pair $p$ into $M(s)$ leads to a consistent mapping by $PT$. -\subsubsection{Induced subgraph isomorphism} $M(s)\cup \{(u,v)\}$ is a consistent mapping by $IND$ $\Leftrightarrow (\forall \tilde{u}\in M_{small}: (u,\tilde{u})\in E_{small} -\Leftrightarrow (v,Pair(M(s),\tilde{u}))\in E_{large})$.\newline The +\Leftrightarrow (v,Pair(M(s),\tilde{u}))\in E_{large})$. The following formulation gives an efficient way of calculating $Cons_{IND}$. \begin{claim} @@ -596,74 +595,27 @@ consistency function in the case of $IND$. \end{claim} -\subsubsection{Graph isomorphism} -$M(s)\cup \{(u,v)\}$ is a consistent mapping by $ISO$ -$\Leftrightarrow$ $M(s)\cup \{(u,v)\}$ is a consistent mapping by -$IND$. -\begin{claim} -$Cons_{ISO}((u,v),M(s))$ is a consistency function by $ISO$ if and - only if it is a consistency function by $IND$. -\end{claim} -\subsubsection{Subgraph isomorphism} -$M(s)\cup \{(u,v)\}$ is a consistent mapping by $SUB$ $\Leftrightarrow -(\forall \tilde{u}\in M_{small}:\\(u,\tilde{u})\in E_{small} -\Rightarrow (v,Pair(M(s),\tilde{u}))\in E_{large})$. -\newline -The following formulation gives an efficient way of calculating -$Cons_{SUB}$. -\begin{claim} -$Cons_{SUB}((u,v),M(s)):= (\forall \tilde{u}\in \Gamma_{small}(u) - \ \cap\ M_{small}(s):\\(v,Pair(M(s),\tilde{u}))\in E_{large})$ is a - consistency function by $SUB$. -\end{claim} - \subsection{Cutting rules} $Cut_{PT}(p,M(s))$ is defined by a collection of efficiently verifiable conditions. The requirement is that $Cut_{PT}(p,M(s))$ can be true only if it is impossible to extended $M(s)\cup \{p\}$ to a whole mapping. + +As an example, the cutting function of induced subgraph isomorphism is presented. \begin{notation} - Let $\mathbf{\tilde{T}_{small}}(s):=(V_{small}\backslash M_{small}(s))\backslash T_{small}(s)$, and \\ $\mathbf{\tilde{T}_{large}}(s):=(V_{large}\backslash M_{large}(s))\backslash T_{large}(s)$. \end{notation} -\subsubsection{Induced subgraph isomorphism} + \begin{claim} $Cut_{IND}((u,v),M(s)):= |\Gamma_{large} (v)\ \cap\ T_{large}(s)| < |\Gamma_{small} (u)\ \cap\ T_{small}(s)| \vee |\Gamma_{large}(v)\cap \tilde{T}_{large}(s)| < |\Gamma_{small}(u)\cap \tilde{T}_{small}(s)|$ is a cutting function by $IND$. \end{claim} -\subsubsection{Graph isomorphism} -Note that the cutting function of induced subgraph isomorphism defined -above is a cutting function by $ISO$, too, however it is less -efficient than the following while their computational complexity is -the same. -\begin{claim} -$Cut_{ISO}((u,v),M(s)):= |\Gamma_{large} (v)\ \cap\ T_{large}(s)| \neq - |\Gamma_{small} (u)\ \cap\ T_{small}(s)| \vee |\Gamma_{large}(v)\cap - \tilde{T}_{large}(s)| \neq |\Gamma_{small}(u)\cap - \tilde{T}_{small}(s)|$ is a cutting function by $ISO$. -\end{claim} -\subsubsection{Subgraph isomorphism} -\begin{claim} -$Cut_{SUB}((u,v),M(s)):= |\Gamma_{large} (v)\ \cap\ T_{large}(s)| < - |\Gamma_{small} (u)\ \cap\ T_{small}(s)|$ is a cutting function by - $SUB$. -\end{claim} -Note that there is a significant difference between induced and -non-induced subgraph isomorphism: - -\begin{claim} -\label{claimSUB} -$Cut_{SUB}'((u,v),M(s)):= |\Gamma_{large} (v)\ \cap\ T_{large}(s)| < -|\Gamma_{small} (u)\ \cap\ T_{small}(s)| \vee |\Gamma_{large}(v)\cap -\tilde{T}_{large}(s)| < |\Gamma_{small}(u)\cap \tilde{T}_{small}(s)|$ -is \textbf{not} a cutting function by $SUB$. -\end{claim} \section{The VF2++ Algorithm} Although any total ordering relation makes the search space of VF2 a