6週4日目 行こうか行くまいか
Determination・stance・judgment
接続：N／普通形＋ではあるまいか
is not; How to state formal judgments
注意 / Note：It is a way of stating one's judgment in a FREQUENT and formal way, equivalent to 〜のではないだろうか but older. Often seen in editorials. Do not use when talking normally.
比較 / Compare：Same song: 〜まい／〜ようか〜まいか. These models are often mistakenly chosen for each other — carefully read the 接続 and nuances above and then decide.
よく出る形 / Common form：名詞・普通形＋ではあるまいか。Usually stands at the end of a paragraph to conclude a statement.
これは大きな問題ではあるまいか。
Isn't this a big problem?
原因は別にあるのではあるまいか。
Perhaps the cause lies elsewhere?
問題の根は、もっと深いところにあるのではあるまいか。
Could it be that the root of the problem lies much deeper?