1 |
1. T : Type
2. L : T List
3. P : ||L|| Prop
4. x: ||L||. Dec(P(x))
5. n :
6. k :
7. f : n  ||L||
8. g : k  ||L||
9. increasing(f;n)
10. increasing(g;k)
11. i: n. P(f(i))
12. j: k. P(g(j))
13. i: ||L||. ( j: n. i = f(j)) ( j: k. i = g(j))
L1,L2:T List, f1:( ||L1||  ||L||), f2:( ||L2||  ||L||).
interleaving_occurence(T;L1;L2;L;f1;f2)
& ( i: ||L1||. P(f1(i))) & ( i: ||L2||. P(f2(i)))
& ( i: ||L||.
& ((P(i)  ( j: ||L1||. f1(j) = i)) & ( P(i)  ( j: ||L2||. f2(j) = i)))
 | 21 steps |