<Tr> <Td> <Ul> <Li> Gradient </Li> <Li> Divergence </Li> <Li> Curl </Li> <Li> Laplacian </Li> <Li> Directional derivative </Li> <Li> Identities </Li> </Ul> </Td> </Tr> <Ul> <Li> Gradient </Li> <Li> Divergence </Li> <Li> Curl </Li> <Li> Laplacian </Li> <Li> Directional derivative </Li> <Li> Identities </Li> </Ul> <Tr> <Th> Theorems </Th> </Tr> <Tr> <Td> <Ul> <Li> Divergence </Li> <Li> Gradient </Li> <Li> Green's </Li> <Li> Kelvin--Stokes </Li> </Ul> </Td> </Tr>

Give a definition for f (x) is continuous at x = a