Let x, y, w, u, v, a, b and c be given.
Assume Hx Hy Hw Hu Hv Ha Hb Hc H1 H2 H3.
We prove the intermediate
claim L1:
b + y < w + u + a.
An
exact proof term for the current goal is
add_SNo_Lt_subprop3b b y w u a c Hb Hy Hw Hu Ha Hc H3 H2.
We prove the intermediate
claim Lxy:
SNo (x + y).
An
exact proof term for the current goal is
SNo_add_SNo x y Hx Hy.
We prove the intermediate
claim Lwuv:
SNo (w + u + v).
We prove the intermediate
claim Lwua:
SNo (w + u + a).
We prove the intermediate
claim Lby:
SNo (b + y).
An
exact proof term for the current goal is
SNo_add_SNo b y Hb Hy.
We will
prove (x + y) + b < (w + u + v) + b.
We will
prove (x + y) + b < x + w + u + a.
rewrite the current goal using
add_SNo_assoc x y b Hx Hy Hb (from right to left).
We will
prove x + y + b < x + w + u + a.
rewrite the current goal using
add_SNo_com y b Hy Hb (from left to right).
We will
prove x + b + y < x + w + u + a.
Apply add_SNo_Lt2 x (b + y) (w + u + a) Hx Lby Lwua to the current goal.
We will
prove b + y < w + u + a.
An exact proof term for the current goal is L1.
We will
prove x + w + u + a < (w + u + v) + b.
We prove the intermediate
claim L2:
x + w + u + a = (w + u) + (x + a).
Use transitivity with
(x + w + u) + a,
(w + u + x) + a, and
w + u + x + a.
An
exact proof term for the current goal is
add_SNo_assoc_4 x w u a Hx Hw Hu Ha.
Use f_equal.
Use symmetry.
Use symmetry.
An
exact proof term for the current goal is
add_SNo_assoc_4 w u x a Hw Hu Hx Ha.
We will
prove w + u + x + a = (w + u) + (x + a).
We prove the intermediate
claim L3:
(w + u + v) + b = (w + u) + b + v.
Use transitivity with
((w + u) + v) + b, and
(w + u) + (v + b).
Use f_equal.
An
exact proof term for the current goal is
add_SNo_assoc w u v Hw Hu Hv.
Use f_equal.
An
exact proof term for the current goal is
add_SNo_com v b Hv Hb.
rewrite the current goal using L2 (from left to right).
rewrite the current goal using L3 (from left to right).
We will
prove (w + u) + (x + a) < (w + u) + (b + v).
An exact proof term for the current goal is H1.
∎