Hello, I am a math major and I was wondering if you guys knew what would be a good rigorous differential equations text. I really like rigor (like Rudin analysis style rigor or whatnot), instead of the typical books that just focus on the method. I want the proofs and everything. I also would like theoretical questions if possible too, and applied as well (I guess it would be hard to find a differential equations text without applications haha). Could anyone tell me if there are any such books? If not, could you at least tell me what your favorite is? I hear Differential Equations with historical notes by Simmons is a good one. Thanks in advance for any response. Sorry if this question is worded weirdly. I'm on mobile in public and can't focus well.