What is the legal implication when a person states an obligation using 'or' (aw) or 'either/or' (imma)?

Primary text

When a person admits, 'I owe him a dirham,' or 'a dinar,' or 'either a dirham or a dinar,' this constitutes an admission of one of the mentioned amounts. Interpretation reverts to the speaker because 'or' (aw) and 'either/or' (imma) in a declarative statement indicate uncertainty and necessitate one of the mentioned items, not the totality of them.