ARI solves a structured prediction problem over a bipartite graph between source and target field paths. The objective is to infer a globally consistent mapping via maximum a posteriori (MAP) inference in a constrained graphical model.
Let the sets of source and target field paths be:
$$ S = \{s_i\} \qquad T = \{t_j\} $$
A mapping is a binary relation $R$:
$$ R \subseteq S \times T $$
Define indicator variables:
$$ x_{s,t} \in \{0,1\}, \quad (s,t) \in S \times T $$
where $x_{s,t}=1$ means that the source $s$ and target $t$ fields are compatible.
Then, equivalently, we can define $R$ as:
$$ R = \{(s,t) \mid x_{s,t} = 1\} $$
ARI defines a Gibbs distribution over mappings:
$$ P(R) \propto \exp\left(-E(R)\right) $$
and seeks the MAP solution:
$$ R^* = \arg\min_R E(R) $$
The energy decomposes into unary and pairwise terms:
$$ E(x) = \sum_{(s,t)\in S\times T} \psi_u(s,t)\,x_{s,t}