Syntax of FOL:Basic elements ·Constants KingJohn,2,NUS,... ·Predicates Brother,>,.. 。Functions Sqrt,LeftLegof,... 。Variables X,y;a,b,... ·Connectives,→，入，V,→ ·Equality ·Quantifiers V,JSyntax of FOL: Basic elements • Constants KingJohn, 2, NUS,... • Predicates Brother, >,... • Functions Sqrt, LeftLegOf,... • Variables x, y, a, b,... • Connectives , , , ,  • Equality = • Quantifiers , 