  The generalized Riordan group consists of infinite lower triangular matrices
that correspond to certain operators in the space of formal power series. Each
such group contains the matrix (generalized Pascal matrix), elements of which
are generalized binomial coefficients. Generalized Pascal matrices with
non-negative elements form an infinite-dimensional vector space. The paper
gives an idea of groups similar to the generalized Riordan groups, but
associated with matrices, which in the space of generalized Pascal matrices
correspond to the points at infinity; examples of such matrices are the matrix
of $q$-binomial coefficients for $q=-1$ and the Pascal triangle modulo $2$. An
analog of the Lagrange inversion theorem for these groups is given and the
corresponding examples are considered.
