pub fn artificial_basis_columns(&self) -> HashSet<usize> {
        self.basis_columns
            .iter()
            .filter(|&&v| v < self.nr_artificial_variables())
            .copied()
            .collect()
    }
/// Get the indices of the artificial variables that are still in the basis.
Get the indices of the artificial variables that are still in the basis.
Get the indices of the artificial variables that are still in the basis .
pub fn artificial_basis_columns(&self) -> HashSet<usize> {
        self.basis_columns
            .iter()
            .filter(|&&v| v < self.nr_artificial_variables())
            .copied()
            .collect()
    }
pub fn artificial_basis_columns ( & self ) -> HashSet < usize > { self . basis_columns . iter ( ) . filter ( | & & v | v < self . nr_artificial_variables ( ) ) . copied ( ) . collect ( ) }
Get the indices of the artificial variables that are still in the basis.
Get the indices of the artificial variables that are still in the basis .
&self
&self