Let $\mathcal{X}$ be a measurable space, Fix $m,q \in \mathbb{N}^*$, and $X = (x_1, \dots, x_m) \sim \mathcal{D}_{\mathcal{X}}^m$. Consider a finite set of functions $\mathcal{F} = \{h_1, \dots h_q\}$ that takes the values:$\{-1,1\}$ We are interested in the following set: $$\mathcal{F}(X) = \Big\{h_1(x_i), \dots h_q(x_i), i \in [m]\Big\}$$ such that at least two elements of $\mathcal{F}$ disagree on $X$ (disagree on all samples $x_1, \dots, x_m$): That is : $$\forall l \in [m], \exists i \neq j \in [q]: h_i(x_l) \neq h_j(x_l)$$ I'm interested in the two following questions : 1- what is a tight upper bound on $|\mathcal{F}(X)|$? 2- what can we say about $\mathbb{E}[|\mathcal{F}(X)|]$? **EDIT:** Previously (before the edit), I represented $\mathcal{F}(X)$ in the matrix form by where each row represent a vector belonging to $\mathcal{F}(X)$,so it can be seen as: $$ \mathcal{F}(X) = \begin{pmatrix} h_1(x_1) & h_2(x_1)& \cdots & h_q(x_1) \\ h_1(x_2) & h_2(x_2)& \cdots & h_q(x_2) \\ \vdots & \cdots & \cdots & \vdots \\ h_1(x_m) & h_2(x_m) & \cdots & h_q(x_m) \end{pmatrix} $$ Counting elements of $\mathcal{F}(X)$ is equivalent to counting different rows in the matrix representation.