What predicative element is left unexpressed in «inna maḥallan wa-inna murtaḥalan»?

Conditions of the Predicate: Ellipsis, Reconstruction and Expression

• Inna itself is omitted in both clauses
• Maḥallan is the agent in both clauses
• Murtaḥalan is a preposition
• A predicative relation such as lanā is understood