Synopsis: Verifiable C is a style of C programming suited to separation-logic verifications; it is similar to the C light intermediate language of the CompCert compiler. We show the assertion language of separation-logic predicates for specifying states of a C execution. The judgment form semax of the axiomatic semantics relates a C command to its precondition postconditions, and for each kind of command there is an inference rule for proving its semax judgments. We illustrate with the proof of a C program that manipulates linked lists, and we give examples of other programs and how they can be specified in the Verifiable C program logic. Shared-memory concurrent programs with Dijkstra-Hoare synchronization can be verified using the rules of concurrent separation logic.