Can you attack through full cover?

An eldritch knight wants to attack a guard behind a wall. Before, he casts scrying and thus can see the target and where they are behind the wall.

How this should be resolved?

Is he unable to attack through the wall? Or it depends on the material of the wall? Or it counts as attacking a location? How should advantage/disadvantage be applied to this?

I really want this to work because having a knight in full plated armor greet the enemy through the wall with a giant axe seem awesome, but my DM insists on giving me ruling support.

Minimum Weighted Vertex Cover, Dynamic Programming

Problem

So my solution in my mind right now:

Let $ OPT(n, boolean)$ be the minimum vertex cover rooted at vertex n that includes that vertex if boolean is true, false otherwise.

So my idea is:

If a vertex is not included, any edges leading away from it, their vertices are to be part of the vertex cover. $ OPT(n, F) = OPT(n.left, T) + OPT(n.right, T)$

If a vertex is included, it can or can not be included, the vertex at the other end of an edge. $ OPT(n, T) = min\{OPT(n.left, T) + OPT(n.right, T), OPT(n.left, F) + OPT(n.right, F), OPT(n.left, F) + OPT(n.right, T), OPT(n.left, T) + OPT(n.right, F)\} + n.weight $

Then we can solve this problem with $ min\{OPT(root, T), OPT(root, F)\}$

Is this the right idea? Is there anything I might be missing? If so, what would be the correct approach?

Can anyone read the inscription on the 3rd edition Forgotten Realms Campaign Setting cover?

The cover for the book in question has inscriptions in the espruar script on its outer circle. According to one of the authors, it means: “ We remember cities now in ruin and forests murdered, yet still we sing to the stars and hope for renewal.”

I’m trying to find out how it’s pronounced in elven. Does anyone have a copy of the book, or a good quality image that they can read?

Can silk stop the raging Orc? or rather do fragile structures provide less cover?

The Player’s Handbook (pg. 196) reads

Walls, trees, creatures, and other obstacles can provide cover during combat, making a target more difficult to harm.

However it only defines degrees of cover (1/2, 3/4, Full) in terms of area covered. RAW it then seems that a curtain of silk provides as much cover cover against the attacks of a battle axe wielding Orc as a stone wall. Reasonably, however, it would make more sense just to confer the benefits of Unseen rather than the benefits of cover.

Rules as Written is there something I am overlooking and if not what is there a more reasonable system of adjudicating cover?

Reducing Vertex Cover to Half Vertex Cover

I need to reduce Vertex Cover to Half Vertex Cover using a Karp reduction:

Vertex Cover: Given a graph $ G = (V,E)$ and an integer $ k$ , is there a subset of $ V$ of size $ k$ which intersects all edges?

Half Vertex Cover: Given a graph $ G = (V,E)$ and an integer $ k$ , is there a subset of $ V$ of size $ k$ which intersects exactly half the edges?

I will be happy if you can tell me how to do that and why the reduction works (both directions of the proof).

Can the cantrip Mold Earth create improvised cover?

the cantrip Mold Earth states:

If you target an area of loose earth, you can instantaneously excavate it, move it along the ground, and deposit it up to 5 feet away. This movement doesn’t have enough force to cause damage.

so the question is if the following graphics are accurate with the assumption that the ground is entirely loose earth

 |   |   |   |  XXXXXXXXXXXOOOOXXXXXXXXXXXXX  XXXXXXXXXXXOOOOXXXXXXXXXXXXX  XXXXXXXXXXXOOOOXXXXXXXXXXXXX  XXXXXXXXXXXXXXXXXXXXXXXXXXXX  XXXXXXXXXXXXXXXXXXXXXXXXXXXX 

move it 3 feet up

 |   |_________OOOO   |_________OOOO   |_________OOOO  XXXXXXXXXXX____XXXXXXXXXXXXXX  XXXXXXXXXXX__^_XXXXXXXXXXXXXX  XXXXXXXXXXX__|_XXXXXXXXXXXXXX  XXXXXXXXXXXXXXXXXXXXXXXXXXXXX  XXXXXXXXXXXXXXXXXXXXXXXXXXXXX 

and then 2 feet over

 |   |____OOOO   |____OOOO <-   |____OOOO  XXXXXXXXXX_____XXXXXXXXXXXXX  XXXXXXXXXX_____XXXXXXXXXXXXX  XXXXXXXXXX_____XXXXXXXXXXXXX  XXXXXXXXXXXXXXXXXXXXXXXXXXXX  XXXXXXXXXXXXXXXXXXXXXXXXXXXX 

(where the Xs and Os are 1/2 a foot wide and each row is 1 foot deep)

so if a humanoid were to stand in the 3 foot deep hole behind the 3 foot high cover that is two feet thick (and most likely 5 feet wide), how much protection would this provide for them? Does it seem reasonable that a PC would be able to erect such a barricade in combat or would it have to be done prior to combat?