Extension subsets:
* **Ztrans**: standard transcendentals (best suited to 3D)
-* **ZtransExt**: extra functions (useful, not generally needed for 3D)
+* **ZtransExt**: extra functions (useful, not generally needed for 3D, can be synthesised using Ztrans)
* **Ztrigpi**: trig. xxx-pi sinpi cospi tanpi
* **Ztrignpi**: trig non-xxx-pi sin cos tan
* **Zarctrigpi**: arc-trig. a-xxx-pi: atan2pi asinpi acospi