Returns a binary relation that represents results
of comparisons with pord
of all pairs of elements in x.
We have ret[i,j] == pord(x[[i]], x[[j]], ...).
rel_graph(x, pord, ...)list with elements to compare, preferably named
a function with two arguments, returning a single boolean value,
e.g. pord_spread,
pord_nd, or pord_weakdom
additional arguments passed to pord
Returns a square logical matrix.
dimnames of the matrix correspond
to names of x.
Other binary_relations: check_comonotonicity,
pord_nd, pord_spread,
pord_weakdom,
rel_is_antisymmetric,
rel_is_asymmetric,
rel_is_cyclic,
rel_is_irreflexive,
rel_is_reflexive,
rel_is_symmetric,
rel_is_total,
rel_is_transitive,
rel_reduction_hasse