{motive : Lean.IR.LogEntry → Sort u} →
  ((cls : Lean.Name) → (decls : Array Lean.IR.Decl) → motive (Lean.IR.LogEntry.step cls decls)) →
    ((msg : Std.Format) → motive (Lean.IR.LogEntry.message msg)) → (t : Lean.IR.LogEntry) → motive t