Dekel et al. (1998) showed that standard state-space models preclude non-trivial unawareness. We argue that their introspection axioms may be too strong and instead explore two new axioms on unawareness, weak KU introspection and U-monotonicity. We show that even if we relax their axioms, when employing these new axioms, we arrive at the same conclusions as theirs. Results illustrate the relationships among various axioms that have not been previously explored. Based on them, we also discuss briefly about the possibility of representing non-trivial unawareness within the standard state-space approach.
