Call by value

In pure lambda calculus, this strategy is defined by the following rules:

• ${\displaystyle \frac{t_1\to t_1^{\prime }}{t_1{t}_2\to t_1^{\prime }{t}_2}}$

• ${\displaystyle \frac{t_2\to t_2^{\prime }}{v_1{t}_2\to v_1{t}_2^{\prime }}}$

• $(\lambda x.t)v\to [x\to v]t$