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that is (to say); namely; i.e.
precisely; exactly; just; nothing but; neither more nor less
(and) then
これすなわち彼の本当の姿である。
This is namely his true self.
答えすなわち解決策はこれだと思う。
The answer, namely the solution, is this.
原因すなわち問題の根本を探そう。
Let's find the cause, namely the root issue.