The uniform Kruskal theorem over RCA$_0$
The uniform Kruskal theorem over RCA$_0$
Kruskal's theorem famously states that finite trees (ordered using an infima-preserving embeddability relation) form a well partial order. Freund, Rathjen, and Weiermann extended this result to general recursive data types with their uniform Kruskal theorem. They do not only show that this principle is true but also, in the context …