{"item_id": "ker-phone_ctx", "crate_dir": "../../bench/kernels/phone_ctx/pre", "lib_name": "k_phone_ctx_pre", "provenance": {"author": "claude-sonnet subagent, blind", "written_from": "signature + doc string only", "saw_source": false, "saw_diff": false, "saw_advisory": false},
 "properties": [
  {"id": "p1", "fn": "context_prefix_skip", "args": [["s", "bytes"]], "pre": "true", "post": "s.first() != Some(&b'+') || r == 1", "ret": "usize", "basis": "1 if it starts with '+'"},
  {"id": "p2", "fn": "context_prefix_skip", "args": [["s", "bytes"]], "pre": "true", "post": "s.first() == Some(&b'+') || r == 0", "ret": "usize", "basis": "otherwise 0 (including empty input, which must not panic)"},
  {"id": "p3", "fn": "context_prefix_skip", "args": [["s", "bytes"]], "pre": "true", "post": "r <= s.len() && r <= 1", "ret": "usize", "basis": "skip is 0 or 1 and never exceeds the input length"}
 ]}