Given a two-body comparison scenario where BOTH mass and distance vary across pairs, the learner predicts which pair has stronger gravitational pull by jointly reasoning over R1 (mass-rule) and R2 (distance-rule), and explains the trade-off when one input pulls one way and the other pulls the other way (e.g., Sun+Mercury closer-but-less-massive vs. Sun+Earth farther-but-more-massive). The learner uses the PR-07-style 5-row fact-system display as a reference card.