Proof Mind is Fundamental and Matter Doesn't Exist

[Mudhammam]

Definitions:
Mind- simply that which produces consciousness. you can think of it as a product of material interactions or its own substance, but either way it cannot be denied mind exists.
Argument:
1. a metaphysically solipsist world (a world where only a mind exists) cannot be proven false due to epistemic limitations.
2. it is unreasonable to presume solipsism is impossible given 1, therefore it must be reasonably granted solipsism is possible.
3. given 2, it is possible for mind to exist in a solipsist (immaterial) world while it is not for matter.
4. there is therefore something that it true of mind but not of matter. this means they cannot be the same thing and mind is not reducible to matter.
5. substance dualism has been proven false due to the interaction problem (substances can only interact via shared properties and substances cannot be fundamental and share properties).
6. therefore, all is mind and monistic idealism entails.

Your assertion in 4 that mind and matter are separable on the assumption that solipsism is a logical possibility is unwarranted. From here you merely beg the question. Why should we grant that simply because the mind can imagine itself to exist independent of any physical components then such a state must be actually possible? What would a mind that precedes matter be like? How could you even begin to speak of its functions or what purposes it might serve? Does it conceive of objects that it has had no experiences of? Does it recall when it is in contemplation and forget when it is distracted? Upon what basis? If mind is inextricable from matter, and neither 1 nor 2 necessitates that that should not be the case, then 3 is not true. How have you solved the "interaction problem" as you call it? If the mind produces only immaterial objects which it then perceives in differentiated form from objects of thought, impelled to call the former material and the latter immaterial, you've merely rephrased "matter" and "mind" as "immaterial A" and "immaterial B," as their properties still differ in all of the respects in which they appear to, and from which the "interaction problem" becomes a problem in the first place. So, what does that solve?