The function Surv2 provides a response data frame which is used in the function ciregic and ciregic_lt. For interval-censored competing risks data, the function Surv2 must use three parameters (v, u, c). For left-truncated and interval censored competing risks data, the function Surv2 must use four parameters (v, u, w, c). If data are partially left-truncated, but all interval-censored, w = 0 for only interval-censored competing risks data.