有人能帮我用伊莎贝尔/霍尔中的下列方程(一阶逻辑)证明X=M吗?
N>=M
forall n. 0=<n<N --> n<M
X=N其中N, M, X是整数常量。n整数变量.
发布于 2019-09-23 13:33:34
只有当变量是自然变量,而不是整数时,才能进行证明,例如使用此证明:
theory Scratch
imports Main
begin
theorem
fixes N M X :: nat
assumes "N ≥ M"
assumes "∀ n. (0 ≤ n ∧ n < N) ⟶ n<M"
assumes "X = N"
shows "X = M"
proof-
have "¬ N > M"
proof
assume "M < N" with `∀ n. _` show False by auto
qed
with `N ≥ M` and `X = N`
show "X = M" by auto
qed
end如果允许整数而不是反例,则为M=-2、N=-1和X=-2.
https://stackoverflow.com/questions/58060895
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