[CynicalBear]

I have no idea what Luther really taught or said about Sola Scriptura. Though I could envision you got your version of what Luther said from Catholic sources which I can just imagine are misquotes. I do know that when he translated into German there were things he inserted that weren’t there in the original Greek. (He translated from the Latin if I remember correctly) He was after all a Catholic and retained much of the Catholic error. I also suppose I don’t care what he, in particular believed. It would be like me using your definition I suppose. The best I have found is here.

Sola scriptura (Latin ablative, "by scripture alone") is the doctrine that the Bible contains all knowledge necessary for salvation and holiness. Consequently, sola scriptura demands only those doctrines are to be admitted or confessed that are found directly within or indirectly by using valid logical deduction or valid deductive reasoning from scripture. However, sola scriptura is not a denial of other authorities governing Christian life and devotion. Rather, it simply demands that all other authorities are subordinate to, and are to be corrected by, the written word of God. (https://en.wikipedia.org/wiki/Sola_scriptura)

I might suggest that what you have indicated as your understanding is more Solo Scriptura which doesn’t work well at all.

[SoothingDave]

Consequently, sola scriptura demands only those doctrines are to be admitted or confessed that are found directly within or indirectly by using valid logical deduction or valid deductive reasoning from scripture.

And who defines what is "valid"?

There is the problem. You admit that your own deductions are "valid" yet deny that to others.