# Entry Path to Formalized Mathematics

Move from set and function semantics into precise Lean and Mathlib statements and content-addressed evidence objects.

[← Return to results](/en/paths/)

This is a suggested learning sequence, not a universal logical dependency or a formal proof.


- Stage 1 · required



## [Set membership](/en/mko/mko-set-membership/?from=%2Fen%2Fpaths%2Fpath-formalized-mathematics-entry%2F%3Ffrom%3D%252Fen%252Fpaths%252F)

Align membership with the formal semantics of Set as a predicate.

[Related questions](/en/explore/?mko=mko-set-membership) [Concept guides](/en/derivations/?q=mko-set-membership)


- Stage 2 · required



## [Function mapping](/en/mko/mko-function-mapping/?from=%2Fen%2Fpaths%2Fpath-formalized-mathematics-entry%2F%3Ffrom%3D%252Fen%252Fpaths%252F)

Align total-function types with the existence of a unique output.

[Related questions](/en/explore/?mko=mko-function-mapping) [Concept guides](/en/derivations/?q=mko-function-mapping)


- Stage 3 · required



## [Tends-to relation](/en/mko/mko-tends-to-relation/?from=%2Fen%2Fpaths%2Fpath-formalized-mathematics-entry%2F%3Ffrom%3D%252Fen%252Fpaths%252F)

Understand the formal filter core of Filter.Tendsto.

[Related questions](/en/explore/?mko=mko-tends-to-relation) [Concept guides](/en/derivations/?q=mko-tends-to-relation)


- Stage 4 · optional



## [Pythagorean theorem](/en/mko/mko-euclid-pythagorean-theorem/?from=%2Fen%2Fpaths%2Fpath-formalized-mathematics-entry%2F%3Ffrom%3D%252Fen%252Fpaths%252F)

Inspect the formal bridge from encyclopedia semantics to vector and side-length models.

[Related questions](/en/explore/?mko=mko-euclid-pythagorean-theorem) [Concept guides](/en/derivations/?q=mko-euclid-pythagorean-theorem)



Path source & statuspath-formalized-mathematics-entry · reviewed

[Original paths JSON](/data/architecture/learning-paths.json)