Implication expressed by negation and conjunction

A statement equivalent to $X \rightarrow Y$ using only $eg$ and $\wedge$ is $eg (X \wedge eg Y)$.

Source: InternLM Lean-Workbook, record lean_workbook_plus_353 (Apache-2.0). The complete source proposition and its explicit variable declarations are preserved. Explicit binder repair: Declare X and Y as propositions, as required by the source logical equivalence. A separate checked example verifies the intended ((X→Y)↔¬(X∧¬Y)) grouping.