This paper considers knowledge convergation problems for different types of intelligence systems with cognitive-based decision-making. The basis is semantic interoperability of knowledge bases, all of which are managed by knowledge metabase of subject domain or several adjacent domains. The concept of using an information system with various intelligent decision support systems provides for the formation of knowledge base rules based on synonyms. To make and to justify decisions in convergent intelligent systems, it is proposed to use two and 3-simplex prisms. 2-simplex prism is more appropriate if analyzed indicators are changing dynamically.
