[h_abelson-sicp-2_ed] ex 1.3 - update the 7-th solution
[h_abelson-sicp-2_ed] ex 1.3 - update the 7-th solution

ordinary-developer/education,ordinary-developer/education,ordinary-developer/education,ordinary-developer/education,ordinary-developer/education,ordinary-developer/education,ordinary-developer/education