You are viewing this question as it will appear in the manual grading interface. Return to the normal view when you are done.

Element pl-order-blocks: DAG grading for proofs

This question illustrates the grading-method="dag" mode of pl-order-blocks, which is especially useful for constructing mathematical proofs.

Prove that $A \land B \land C \rightarrow A \land C$

This example uses the attribute grading-method="dag" to accept any valid topological ordering. The depends attribute on each block specifies which other blocks must appear before it.

Drag from here:

Construct your solution here:

Correct answer

Correct answer (there may be other correct orders):

Assume $A \land B \land C$.
Then $A$ is true.
Then $C$ is true.
Since $A$ and $C$, we know $A \land C$

Student view placeholder

In student views this area is used for assessment and score info.

Tools

Staff information

Question

QID:

element/orderBlocksDag

Title:

Element pl-order-blocks: DAG grading for proofs

Variant

Started at:

2026-08-04 21:53:30 (CDT)

Duration:

Show/Hide answer

{
  "conjunction-implies-conjunction": [
    {
      "tag": "1",
      "uuid": "d1ed1bdd-66e5-495c-9de8-c56a51e60b2a",
      "final": false,
      "index": 0,
      "indent": null,
      "depends": [],
      "ranking": -1,
      "group_info": {
        "tag": null,
        "depends": null
      },
      "inner_html": " Assume $A \\land B \\land C$.",
      "distractor_for": null,
      "initially_placed": false,
      "ordering_feedback": null,
      "distractor_feedback": null
    },
    {
      "tag": "2",
      "uuid": "bb7c1a8d-ba8c-40f3-bd90-8d411abcd693",
      "final": false,
      "index": 1,
      "indent": null,
      "depends": [
        "1"
      ],
      "ranking": -1,
      "group_info": {
        "tag": null,
        "depends": null
      },
      "inner_html": " Then $A$ is true. ",
      "distractor_for": null,
      "initially_placed": false,
      "ordering_feedback": null,
      "distractor_feedback": null
    },
    {
      "tag": "3",
      "uuid": "e80d4f2b-9b31-4597-a04b-7ddc9cc5b35c",
      "final": false,
      "index": 2,
      "indent": null,
      "depends": [
        "1"
      ],
      "ranking": -1,
      "group_info": {
        "tag": null,
        "depends": null
      },
      "inner_html": " Then $C$ is true. ",
      "distractor_for": null,
      "initially_placed": false,
      "ordering_feedback": null,
      "distractor_feedback": null
    },
    {
      "tag": "4",
      "uuid": "a6e8bdd4-c657-487b-a5d7-510d3e5eb6f3",
      "final": false,
      "index": 3,
      "indent": null,
      "depends": [
        "2",
        "3"
      ],
      "ranking": -1,
      "group_info": {
        "tag": null,
        "depends": null
      },
      "inner_html": " Since $A$ and $C$, we know $A \\land C$",
      "distractor_for": null,
      "initially_placed": false,
      "ordering_feedback": null,
      "distractor_feedback": null
    }
  ]
}

This box is not visible to students.