Can I use [gravitymath] with [gvlogic]?

The answer to the question "Can I use [gravitymath] with [gvlogic]?" is: it depends on what you mean.

If you want to place [gravitymath] shortcodes inside [gvlogic] shortcodes, you can.

This code:

[gvlogic if="1" is="100"] <br>
  One plus two equals: [gravitymath] 1 + 2 [/gravitymath] <br>
[else]
  One hundred and twenty times two equals: [gravitymath] 120 * 2 [/gravitymath] 
[/gvlogic]

Will output as:

One plus two equals: 3

If you meant "Can I use [gv_math] output as parameters for my [gvlogic] shortcode?", the answer is no.

This won't work:

[gvlogic if="3" is="[gravitymath] 1 + 2 [/gravitymath]"] His logic is sound. [/gvlogic]

The reason is a recent change to WordPress itself. Because of a security issue, WordPress made a change so that you are not able to use another shortcode to call a shortcode. Because of this, the [gvlogic] shortcode no longer supports passing the output of the [gravitymath] shortcode inside it.