/// Construct a permutation of length `a.len() + b.len()`.
///
/// Mathematically speaking, this computes the "direct sum" of two permutations.
///
/// The inserted elements will be shifted by this permutation's length,
/// so that they operate on an entirely independent set of data from
/// the existing elements.


The inserted elements will be shifted by this permutation's length,
so that they operate on an entirely independent set of data from
the existing elements.
The inserted elements will be shifted by this permutation ' s length so that they operate on an entirely independent set of data from the existing elements .
pub fn append_mut(&mut self, other: &Perm)
    {
        // (a direct sum of inverses is the inverse of the direct sum)
        self.inv.append_mut(&other.inv);
    }
pub fn append_mut ( & mut self , other : & Perm ) { // (a direct sum of inverses is the inverse of the direct sum) self . inv . append_mut ( & other . inv ) ; }
Construct a permutation of length `a.len() + b.len()`.
Construct a permutation of length ` a . len () + b . len () ` .
&mut self
other
&Perm