error-object? -- vonuvoli Definition type-predicate;
error-object? (from r7rs);Procedure variants:
((error-object |1...|) -> (true))
error-object;... -- at least one time;true;((any |1...|) -> (false))
vs:errors -- (vonuvoli errors);vs:base -- (vonuvoli base);error-object;true;any;false;