## PROOF OF ALGORITHMS BY GENERAL SNAPSHOTS (1966)

BIT 6(4): 310-316, 1966.

### Abstract

A constructive approach to the question of proofs of algorithms is
to consider proofs that an object resulting from the execution of an
algorithm possesses certain static characteristics. It is shown by an
elementary example how this possibility may be used to prove the
correctness of an algorithm written in ALGOL 60. The stepping stone of
the approach is what is called General Snapshots, i.e. expressions of
static conditions existing whenever the execution of the algorithm
reaches particular points. General Snapshots are further shown to be
useful for constructing algorithms.