What is the ruling when a marriage contract specifies a dower (mahr) for one wife but not the other in a plural marriage?

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The marriage is void in the wife for whom no dower was named, as her marriage contract lacked a dower apart from the other wife's contract. For the wife for whom a dower was named, there are two established narrations concerning its validity, because that contract involves both a dower specification and a condition, resembling a case where a specific dower is named for each wife. Abu Bakr opined that the entire marriage (to both) is void because the invalidity in one necessitates invalidity in the other.