 The \(\lambda\) operators allows us to abstract over \(x\). One can intuitively read ‘\(\lambda x[x^2 -2\cdot x+5]\)’ as an expression that is waiting for a value \(a\) for the variable \(x\). When given such a value \(a\) (such as the number 2), the value of the expression is \(a^2 -2\cdot a+5\). The ‘\(\lambda\)’ on its own has no significance; it merely binds the variable \(x\), guarding it, as it were, from outside interference. The terminology in \(\lambda\)-calculus is that we want to apply this expression to an argument, and get a value. We write ‘\(Ma\)’ to denote the application of the function \(M\) to the argument \(a\). Continuing with the example, we get: