Did you get more than me? pt. 2

[BMAD]

Four men (A, B, C, and D) are kept in a room a punishment for their crimes.  Each day, they retreat to a corner where they are fed an amount of a certain type of food.  In total, they receive thirteen pieces of the assigned food.  On this day, they all retreated to their corners to receive beef jerky.  After enjoying their food, they came back to the center.  In front of the group, A asked B, "Did you get more than me?" To which B replied, I don't know.  Curious then, B turned to C and said, "Did you get more than me?" To which C replied, I don't know. Even more curious, C turned to D and said, "Did you get more than me?" To which D replied, "Yes and I know how much each of you got!"

How much food did A and D get?

[gavinksong]

Assuming all the men are highly intelligent,

Spoiler

B must have received more than 1 and less than 6. Otherwise, he would know that he had received either the most or the fewest.

By similar logic, C must have received more than 2 and less than 6. This is all we can infer at this point.

For D to know exactly how much everybody else got, he must have gotten the maximum amount of food possible at this point.

Thus, A must have received 1 piece, B must have received 2, C must have received 3, and D must have received 7.