subsetsearch: Search subsets for a property which is inherited in a...
In SparseMSE: 'Multiple Systems Estimation for Sparse Capture Data'

The following routine returns a list of all subsets of a given set for which a specified property is TRUE. It is assumed that if the property is FALSE for any particular subset, it is also FALSE for all supersets of that subset. This enables a branch search strategy to be used to obviate the need to search over supersets of subsets already eliminated from consideration. It is used within the hierarchical search step of checkallmodels.

1	subsetsearch(n, checkfun, testnull = TRUE, ...)

`n`	an integer such that the search is over all subsets of \{1,...,n\}
`checkfun`	a function which takes arguments `zset`, a subset of \{1,...,n\} and ... The function returns the value `TRUE` or `FALSE`. It needs to have the property that if it is `FALSE` for any particular `zset`, it is also `FALSE` for all supersets of `zset`.
`testnull`	If `TRUE`, then include the null subset in the search. If `FALSE`, do not test the null subset.
`...`	other arguments