SYSE.42:4.2 - Execute within the interface’s effect boundary

Check the expression or layout against the required operation. For a structured call, validate syntax and then its state-dependent meaning: a well-formed request can concern the wrong configuration or a superseded target. Use the current-state precondition when intervening changes matter. Perform the supported operation with the selected means.

For a state-changing software call, retain the attempt identity when recovery needs it. Distinguish rejection before effect, acknowledged progress, confirmed result and unresolved effect. Follow SYSE.26’s same-attempt recovery when an effect may have occurred. Replay is justified only by the interface’s actual retry semantics and observed state; a timeout alone does not supply that basis.

Keep the effort and waiting within the task’s remaining budget. SYSE.40 supplies combined resource and retry limits when several calls or services share them. On exhaustion, return the unfinished condition and recoverable state.