Which function links اِسْتَكْبَرَ and تَكَبَّرَ?

Ten Semantic Functions of Form X (Istifʿāl): Seeking, Suitability, Finding, Judging, Transformation, Adoption, Abbreviation, Response, Equivalence and Independent Use

• Physical transformation
• Equivalence with Form V
• Suitability
• Abbreviation