FirstDescent

The smallest descent position, or 0 when p is increasing.

FirstDescent(p)

Domain: Permutation statistics

Details

• Defined over `Permutation` as an expression in `_x`, evaluated by compute-engine — the definition IS the implementation.
• Takes a `Permutation`, and also a bare list of integers: this reading compares entries with each other rather than with their positions, so it stands on any sequence.

Examples