Involving csc-1(1/1+c z21/2)
Involving csc-1(1/1-z21/2) and sech-1(1/z)
Involving csc-1(1/z2+11/2) and sech-1(1/1+2 z2)
Involving csc-1(1/z2+11/2) and sech-1(1/(z2+1)1/2)