Article 12 — Definition of State
For Part III, "State" includes Parliament, state legislatures, Central and state governments, and all local or other authorities within India or under government control. The test for "other authorities" (from Rajasthan SEB v. Mohan Lal) is whether the body is an instrumentality or agency of the government.
Article 13 — Laws inconsistent with Fundamental Rights
Pre-constitutional laws that are inconsistent with FRs become void to the extent of inconsistency. Post-constitutional laws are void ab initio if they violate FRs. "Law" includes ordinances, orders, bye-laws, rules, regulations, notifications, customs, and usages.
Article 14 — Right to Equality
Two facets: (1) Equality before law (British concept — no man is above law), and (2) Equal protection of laws (American concept — likes should be treated alike). Intelligible differentia + rational nexus test applies to classification. Arbitrariness is the enemy of Article 14 (E.P. Royappa v. State of Tamil Nadu).