This directory contains the files for assignment 3. The files directly relevant for the assignement are: sources.cm : Configuration file ctx.sml : Contains definition of context and functions for looking up elements in a context prop.sml : Contains definition of proposition YOU NEED TO IMPLEMENT EXERCISE 2 IN THIS FILE. WRITE A FUNCTION TO COMPUTE POSITIVE AND NEGATIVE SUBFORMULAS grpover.sml : THIS FILE YOU NEED TO FILL IN FOR EXERCISE 3. It currently contains the skeleton for the guided prover. tests.sml : Some test cases; add your own in a similar manner to generate more FOR THE AMBITIOUS: bi-check.sml : Contains a bi-directional proof checker for normal proofs grpover-checked.sml : THIS IS THE FILE YOU NEED TO WORK ON It currently contains the skeleton for the guided prover. Modify your previous implementation appropriately such that it generats proof terms.