The the unreal nature of form time and space of the waking experience is exposed when the waking entity becomes aware of the fact that, it itself is not the self

 It is just like one and the same water becoming snow, and cloud. The substance is one and the same. If it is not cloud or snow it remains as water. In the same way, without the three states consciousness alone prevails because All the three states are mere mirage created out of consciousness.

 The three states come and go in succession but the knowing principle, the Awareness, remains one and the same in all the three states. The formless, witness, who is in the form of consciousness, remains same through all the experiences.

The dream is parallel waking and waking is parallel dream. The formless knower that knows the coming and going of the three states is one.  Thus on the base of the formless knower the three states are mere mirage. When the mirage is mentally dropped after realization of their unreal nature, the duality will never be experienced as reality again.

 The unreal nature of the experience of form, space, time & objects within the dream becomes unreal when waking takes place. The  unreal nature of   form time and space of the waking experience is exposed when the waking entity becomes aware of the fact that, it itself  is not the self, but the true self is that which sees all the three states as passing show.  

The form, time and space are reality within the waking or dream. But from the standpoint from the formless sources from where they arise and subside they are non-existent.  The formless source is consciousness. The consciousness is the true self. Waking or dream or mere mirage created out of the consciousness.  The nature of the Consciousness is oneness.  Thus the waking or dream not differs from each other because they are mere mirage created out of consciousness. Thus they are both are one in essence.