Update chapters/interface.tex

Co-authored-by: Elena Shmoylova <eshmoylova@users.noreply.github.com>

chapters/interface.tex

@@ -592,7 +592,7 @@ \section{Type Compatible Expressions}\label{type-compatible-expressions}
 \item \lstinline!if!-expressions, e.g.\ \lstinline!if x then A else B!.
 \item Array expressions, e.g.\ \lstinline!{A, B}!
 \item Binary operators if both operands are of simple types, e.g.\ \lstinline!A + B!.
-Binary operators for other types is only defined for operator records, \cref{overloaded-binary-operations} and do not necessarily require that the operands are type compatible with each other.
+Binary operators for other types are only defined for operator records, \cref{overloaded-binary-operations}, and do not necessarily require that the operands are type compatible with each other.
 \end{itemize}
 The resulting type of the expression in case of two type compatible subexpressions \lstinline!A! and \lstinline!B! is defined as follows:
 \begin{itemize}