// Swap things around to the same effect, but as if we were gaining
        // a mutation, or return early if deleting the mutation is never
        // a problem.
        switch(mutat)

        // Swap things around to the same effect, but as if we were
        // gaining a mutation, or return early if deleting the mutation
        // is never a problem.
        switch (mutat)

        // These are mutations which should be cleared away if
        // forced.

        // These are mutations which should be cleared away if forced.

        // If we have one of the pair, delete all levels of
        // the other, and continue processing.

        // If we have one of the pair, delete all levels of the other,
        // and continue processing.

    // These are mutations which can't be traded off against each
    // other, so we just fail.

    // These are mutations which can't be traded off against each other,
    // so we just fail.

            // If we have one of the pair, delete a level of the
            // other, and that's it.

            // If we have one of the pair, delete a level of the other,
            // and that's it.

                return (1);     // Nothing more to do

                return (1);     // Nothing more to do.

            // breathe poison replaces spit poison (so it takes the slot)

            // Breathe poison replaces spit poison (so it takes the slot).