Abstract:
Let $\wp$ be some subgroup property and $n$ is a natural number. A formation $\mathfrak F$ is called $\wp_n$-recognizable if $\mathfrak F$ contains each group $G$ having $n$$\wp$-subgroups belonging $\mathfrak F$. In the paper an original method, based on the concept of T-models for study $\wp_n$-recognizable formations is proposed.
Keywords:finite group, local formation, local screen, T-model, $\wp_n$-recognition.