Bayes Decision Boundary

I agree that all of those implications could be drawn from from knowing that MASS::mvrorm was used to generate the matrices

             [,1]        [,2]
 [1,] -0.527796456 -0.72467316
 [2,] -0.462147562  0.50428239
 [3,] -0.681117039  1.47324304
 [4,]  2.158980267  1.88261815
 [5,]  1.771674308  3.53047590
 [6,]  1.797841356 -4.80572219
 [7,] -0.896777100 -0.67995561
 [8,]  0.056029156 -2.57703471
 [9,] -0.036139940 -1.68664178
[10,]  1.036021910 -0.82579020

but there's more than one thing you can do with a matrix, of course, and the function is not limited to any particular model. That's why I thought that the question should specify a reproducible example, called a reprex to see where the OP was stuck. There are times when it's reasonable to guess what the question is, but as posed, this one is more of a puzzle.