Everything the engine can actually evaluate

Anything not on this list is refused when you ask for it. That matters more than the length of the list: an engine that accepts an unknown name treats the condition as false forever, so the strategy is created, reports itself active and never trades. Nothing here does that.

The operator list is four, not the seven the engine can still read. Three were retired on purpose: on a continuous series greater-or-equal and greater differ only at an exact-equality instant that floating point essentially never produces, and equality itself is worse than redundant, because a condition that never fires builds a strategy that reports itself active and stays silent.