Update Coq proofs of the examples.

...llman_ford/bellman_ford_Graph_long_path_decomposition_1.v

examples/bellman_ford/bf_Graph_key_lemma_1_1.v

examples/bellman_ford/bf_Graph_simple_path_1.v

...man_ford/bf_WP_BellmanFord_WP_parameter_bellman_ford_17.v

...man_ford/bf_WP_BellmanFord_WP_parameter_bellman_ford_18.v

...man_ford/bf_WP_BellmanFord_WP_parameter_bellman_ford_20.v

...les/bellman_ford/bf_WP_BellmanFord_WP_parameter_relax_7.v

examples/bellman_ford/bf_WP_BellmanFord_key_lemma_2_1.v

examples/my_cosine/my_cosine_M_WP_parameter_my_cosine_1.v