Kepler's law vs Kepler's law of planetary motion

Kepler's law and Kepler's law of planetary motion both are nouns.

Word	Noun	Adjective	Verb	Adverb
Kepler's law	Yes	No	No	No
Kepler's law of planetary motion	Yes	No	No	No

As nouns, Kepler's law and Kepler's law of planetary motion are synonyms defined as:

Kepler's law and Kepler's law of planetary motion: (astronomy) one of three empirical laws of planetary motion stated by Johannes Kepler

Kepler's law (noun)	Kepler's law of planetary motion (noun)
(astronomy) one of three empirical laws of planetary motion stated by Johannes Kepler	(astronomy) one of three empirical laws of planetary motion stated by Johannes Kepler