'A' meets 'B' on a highway, shows a pistol, and demands 'B's purse under threat of instant harm. 'B' surrenders the purse. 'A' has committed the offence of:

A finds a government promissory note belonging to Z with a blank endorsement. A, knowing that the note belongs to Z, pledges it with a banker as security for a loan, intending to restore it to Z at a future time. What offence has A committed?