@CV FWIU, the law was not on the books. There was wording in the law that said "substantially equivalent", but what that meant was not stated. For years some individuals have been requesting that the state clarify those words and enforce them. Over the last few years a couple of failed attempts were made, but this week they finally passed a set of guidelines.
NYS Education Law with "substantial equivalence" was passed in 1895, and amended a few times since.
New York law on mandatory educational clearly requires that “each minor from seven to sixteen years of age shall attend upon full time day instruction” (Education Law, art. 65, § 3205, subd. 1). This instruction must include “at least the eleven common school branches of arithmetic, reading, spelling, writing, the English language, geography, United States history, civics, hygiene, physical training and the history of New York State” (Education Law, art. 65, § 3204, subd. 3).