そうにないUnlikely to, Showing no signs of

Compared to そうもない 'very unlikely to (A)', そうにない is a grammar structure that has a very similar meaning, but is not quite as emphasized. In this expression, も will be replaced with に. Also, apart from indicating that something is very unlikely, it may also indicate that something is showing 'no signs of (A)'.

そうにない will connect to the ます-stem of the verb that it is indicating as being very unlikely.

Occasionally, そうにもない may also appear, and has the strongest nuance of being unlikely to happen amongst そうにない, そうもない, and そうにもない. Note that the only difference between these three structures is the addition, subtraction, or combination of the に and も particles.

As this structure is just an extension of the use of the auxiliary verb そう (used primarily for speculation, or hearsay), it is simply indicating that (A) does not have any appearance of occuring.