Having trouble making sense of the sentence "解いてから帰らないとすっきりしないんだ"

Question

In the sentence 解いてから帰らないとすっきりしないんだ, from the context I know it means "If I don't go home after solving it, it won't be refreshing" but I just can't make sense of the grammar, below are the two ways I am thinking about it:

I must solve it then go home (NOTHING) I won't be "relieved" (considering と to be an abbreviation of 帰らないといけない)

If I solve it then don't go home I won't be relieved (assume と is just a normal conditional と)

Can anyone explain it differently to help my brain understand why it means what it does without context?

Answer 1

The と is a normal conditional と.

The scope of the negation (～ない) is the whole 解いてから帰る, not just 帰る.
I think you can think of it this way:

［解いてから帰(る)］+ ないと、すっきりしないんだ
→ If I don't do "解いてから帰る", I won't be relieved.
→ lit. If I don't [go home after solving it], I won't be relieved.
i.e. If I don't solve it before going home, I won't be relieved.

Some example sentences with this structure that I think you might come across in daily life:

「豚肉は加熱してから食べないといけません。」
「予約してから行かないと待たされます。」
「化粧を落としてから寝ないと肌に悪いですよ。」
「体を洗ってから湯船に入らないとダメですよ。」
「お互いのことをよく知ってから結婚しないと、うまくいかないと思います。」

Answer 2

I think you could look at it this way.

から binds 解く and 帰る closer to each other than 帰る is bound to ないと. Thus, 解いてから帰る refers to an act of doing those two things in that order. Unless you do that, your mind won’t get cleared.

The second interpretation is not completely impossible but から sounds a bit jarring in that case. 解いて帰らないと would be more ambiguous, in which case you might need to rely on the way the sentence is pronounced to get the correct meaning.