The central logical skills are developed in the LogicLab lab environment mentioned earlier. In derivation problems, students practice proof construction in a natural deduction framework.

Here their learning is supported by an intelligent automated tutor. This Proof Tutor helps students, on demand and dynamically, to think through arguments in a systematic and strategic fashion. The Proof Tutor uses the automated proof search mechanism AProS to provide, as part of the dialogue with the student, strategically informed hints for solving proof problems. 

In the semantic truth-table and truth-tree problems, students practice techniques for a semantic analysis of formulae and arguments. They begin with "chasing truth up the tree of grammar", in Quine's vivid language; then they complete truth-tables and build truth-trees for sentential and predicate formulae involving identity.  Ultimately, they learn how to define counterexamples to incorrect arguments using a completed truth-tree.