This is completely incorrect. There are two inputs and one output, e.g., ℝ⨯ℝ→ℝ. Since there are two inputs, it's a binary operator. Since there are three inp

This is completely incorrect. There are two inputs and one output, e.g., ℝ⨯ℝ→ℝ. Since there are two inputs, it's a binary operator. Since there are three inputs and outputs combined, it's a ternary relation. Likewise, a unary operator is a binary relation. For example, x ↦ -x, or x ↦ x+1.