1. noun form returned ok:
(%i9) integrate(acos(1+%i*x),x,1,2);
(%o9) 'integrate(acos(%i*x+1),x,1,2)
2. Maxima hangs and used ^C in console mode
to get back prompt.
(%i10) integrate(acos(1+%i*x),x,-1,2);
Maxima encountered a Lisp error:
Console interrupt.
Automatically continuing.
To enable the Lisp debugger set *debugger-hook* to nil.
Ted Woollett
(v.5.25.1gcl, windows)