Metamath Proof Explorer


Theorem fsuppmapnn0fz

Description: If a function over the nonnegative integers is finitely supported, then there is an upper bound for a finite set of sequential integers containing the support of the function. (Contributed by AV, 30-Sep-2019) (Proof shortened by AV, 6-Oct-2019)

Ref Expression
Assertion fsuppmapnn0fz F R 0 Z V finSupp Z F m 0 F supp Z 0 m

Proof

Step Hyp Ref Expression
1 fsuppmapnn0ub F R 0 Z V finSupp Z F m 0 x 0 m < x F x = Z
2 simpllr F R 0 Z V m 0 x 0 m < x F x = Z Z V
3 simplll F R 0 Z V m 0 x 0 m < x F x = Z F R 0
4 simplr F R 0 Z V m 0 x 0 m < x F x = Z m 0
5 simpr F R 0 Z V m 0 x 0 m < x F x = Z x 0 m < x F x = Z
6 2 3 4 5 suppssfz F R 0 Z V m 0 x 0 m < x F x = Z F supp Z 0 m
7 6 ex F R 0 Z V m 0 x 0 m < x F x = Z F supp Z 0 m
8 7 reximdva F R 0 Z V m 0 x 0 m < x F x = Z m 0 F supp Z 0 m
9 1 8 syld F R 0 Z V finSupp Z F m 0 F supp Z 0 m