  One observes that a considerable level of confusion remains about some of
those aspects of irreversibility, entropy generation and `the arrow of time'
which actually are well understood. This demands that great care must be taken
in any discussion of irreversibility to use clear-cut notions and precise
language in order to be definite about which property follows from which
assumption. In this work, a novel toy model of `algebraic mechanics' is
presented that elucidates specific key aspects of entropy generation in a
system with extremely simple reversible fundamental dynamics. It is argued why
insights gained through a detailed quantitative study of this toy model also
have to be taken into account for any realistic model of microscopic dynamics,
classical or quantum alike. As irreversibility also touches upon the quantum
mechanical measurement process (through the `proof' of the `H-Theorem'), a
simple way to address the tenacious question `when (and how) the wave function
collapses' is offered.
