\BOOKMARK [1][]{Outline1}{Main Part}{} \BOOKMARK [2][]{Outline1.1}{History}{Outline1} \BOOKMARK [3][]{Outline1.1.1.4}{Enumerability in Recursion and Automata Theory}{Outline1.1} \BOOKMARK [3][]{Outline1.1.2.16}{Known Weak Cardinality Theorem}{Outline1.1} \BOOKMARK [3][]{Outline1.1.3.23}{Why Do Cardinality Theorems Hold Only for Certain Models?}{Outline1.1} \BOOKMARK [2][]{Outline1.2}{Unification by First-Order Logic}{Outline1} \BOOKMARK [3][]{Outline1.2.1.28}{Elementary Definitions}{Outline1.2} \BOOKMARK [3][]{Outline1.2.2.32}{Enumerability for First-Order Logic}{Outline1.2} \BOOKMARK [3][]{Outline1.2.3.34}{Weak Cardinality Theorems for First-Order Logic}{Outline1.2} \BOOKMARK [2][]{Outline1.3}{Applications}{Outline1} \BOOKMARK [3][]{Outline1.3.1.42}{A Separability Result for First-Order Logic}{Outline1.3} \BOOKMARK [2][]{Outline1.4}{Summary}{Outline1}