That's great and you have sent me down the rabbit hole.
So, usage would be something like:
CardPower ← {+⌿⍤2(∘.≤)⍤1⍨⍵}
CardPower cardMatrix
So, usage would be something like:
CardPower ← {+⌿⍤2(∘.≤)⍤1⍨⍵}
CardPower cardMatrix
Thanks for that follow up comment.