Before revision:  The first pillar is the principle of meaning preservation \mathcal{M}: it measures to what extent the original AMR graph can be reconstructed from the generated sentence . We implement this principle by i) automatically constructing an AMR from the generated sentence using state-of-the-art AMR parsers and ii) apply fine-grained principled AMR metrics to measure the distance between the original and the reconstructed AMR. The second pillar builds on a principle of (grammatical) form \mathcal{F} , which measures the linguistic quality of the generated sentences , which we implement using SOTA language models.
After revision:  The first pillar is the principle of meaning preservation \mathcal{M}: it measures to what extent the original AMR graph can be reconstructed from the generated sentence using SOTA AMR parsers and ii) apply fine-grained principled AMR metrics to measure the distance between the original and the reconstructed AMR. The second pillar builds on a principle of (grammatical) form \mathcal{F} , which measures the linguistic quality of the generated sentences , which we implement using SOTA language models.