#5209 trigexpand ignores triginverses + trigexpandplus is not evflag

[David Scherfgen]

(%i1) block([triginverses:false], string(trigreduce(tan(atan(x+y+z)))));
(%o1) z+y+x

And trigexpandplus should be an evflag:

(%i1) trigexpandplus : false$

(%i2) trigexpand(sin(x+y)), trigexpandplus;
(%o2) sin(y+x);