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+**Preface**
+
+This exists because we believe learning math should be enjoyable for everyone. These notes are meant as a reference for anyone studying the same topics and wanting a cross-reference.
+
+Since doing this alone, we couldn't cross-reference with anyone else. So this preface is an invitation: create and publish your own notes. If you can't create or publish solo, maybe we can start a math club — a more laid-back format to share things.