  In this paper we first generalize to the case of partial flags a result
proved both by Spaltenstein and by Steinberg that relates the relative position
of two complete flags and the irreducible components of the flag variety in
which they lie, using the Robinson-Schensted-Knuth correspondence. Then we use
this result to generalize the mirabolic Robinson-Schensted-Knuth correspondence
defined by Travkin, to the case of two partial flags and a line.
