Next migration

Read side by side

The logarithm, exponential, and power family is now complete. The next major block is trigonometric and hyperbolic functions.

Required shared core

1. certified reduction by pi/2 using the independent pi cache;
2. exact quadrant and signed-zero handling;
3. a paired sin_cos kernel with one Ziv-style evaluator;
4. tangent, secant, cosecant, and cotangent from the paired kernel;
5. inverse trigonometric functions and two-argument atan2;
6. a paired sinh_cosh kernel built on the completed exponential family;
7. scaled-unit and pi-scaled interfaces.

The existing transcendental evaluator should remain the public correctness shell. Faster series, binary splitting, and table methods can be introduced underneath it without changing the numerical contract.