Long horizon robotic tasks are hard due to contin
uous state action spaces and sparse feedback. Symbolic world
models help by decomposing tasks into discrete predicates that
capture object properties and relations. Existing methods learn
predicates either top down, by prompting foundation models
without data grounding, or bottom up, from demonstrations
without high level priors. We introduce UniPred, a bilevel
learning framework that unifies both. UniPred uses large lan
guage models (LLMs) to propose predicate effect distributions
that supervise neural predicate learning from low level data,
while learned feedback iteratively refines the LLM hypotheses.
Leveraging strong visual foundation model features, UniPred
learns robust predicate classifiers in cluttered scenes. We further
propose a predicate evaluation method that supports symbolic
models beyond STRIPS assumptions. Across five simulated and
one real robot domains, UniPred achieves 2 ∼ 4× higher success
rates than top down methods and 3 ∼ 4× faster learning than
bottom up approaches, advancing scalable and flexible symbolic
world modeling for robotics.