file in one Arduino library #include file from another Arduino library

Can a file in one Arduino library #include a file from another Arduino library?
This would be quite useful.

The following example does not work.

Arduinio library directory:
Arduino\libraries\lib_A\A_class.h
Arduino\libraries\lib_B\B_class.h

Arduino\libraries\lib_A\A_class.h

#ifndef A_CLASS_H
#define A_CLASS_H

#include <B_class.h>		//B_class.h is in another library

class A_class : public B_class	//eror: expected class-name before '{' token
{
	int val;
};
#endif

Arduino\libraries\lib_B\B_class.h

#ifndef B_class_H
#define B_class_H

class B_class
{
};
#endif

kb.ino:

#include <A_class.h>

void setup()
{
	A_class a_obj;
}

void loop()
{
}

output:

In file included from kb.ino:1:
C:\Users\wolf\Documents\Arduino\libraries\lib_A/A_class.h:7: error: expected class-name before ‘{’ token

Thank you.

Because of the way the compile is done, you pretty much have to include both <A_class.h> and <B_class.h> in your main sketch, if if the sketch code only has direct dependencies on A_class.
https://github.com/arduino/Arduino/issues/2448

Thanks westfw. That works :) .