API documentation for DecomposeIntoTimeStepsCA is confusing.

[cgranade]

As per discussions in #178, the notation used by DecomposeIntoTimeStepsCA is different than the notation used in the reference cited by that operation (namely, quant-ph/0508139).

Thanks for pointing out the difference between the paper quant-ph/0508139 and the proposed change Chris!

We can better match the notation of the paper by putting the missing factor of two into
let stepSizeOuter = _TrotterStepSize(order/2);
&
return 1.0 / (4.0 - PowD(4.0, 1.0 / (IntAsDouble(2*order) - 1.0)));

instead of the proposed change
let stepSizeOuter = _TrotterStepSize(order);
&
return 1.0 / (4.0 - PowD(4.0, 1.0 / (IntAsDouble(order) - 1.0)));

That said, proposed change is indeed consistent with the paper.
—@guanghaolow

This creates confusion in trying to specify inputs to DecomposeIntoTimeStepsCA, such that a remark should be added to clarify this distinction.