Step
*
of Lemma
select_firstn
∀[T:Type]. ∀[as:T List]. ∀[n:{0...||as||}]. ∀[i:ℕn]. (firstn(n;as)[i] = as[i] ∈ T)
BY
{ (% Rearrange for induction %
Assert ⌜∀T:Type. ∀n:ℕ. ∀as:T List. ((n ≤ ||as||)
⇒ (∀i:ℕn. (firstn(n;as)[i] = as[i] ∈ T)))⌝
THENM (HypBackchain THEN Auto)
) }
1
.....assertion.....
∀T:Type. ∀n:ℕ. ∀as:T List. ((n ≤ ||as||)
⇒ (∀i:ℕn. (firstn(n;as)[i] = as[i] ∈ T)))
Latex:
Latex:
\mforall{}[T:Type]. \mforall{}[as:T List]. \mforall{}[n:\{0...||as||\}]. \mforall{}[i:\mBbbN{}n]. (firstn(n;as)[i] = as[i])
By
Latex:
(\% Rearrange for induction \%
Assert \mkleeneopen{}\mforall{}T:Type. \mforall{}n:\mBbbN{}. \mforall{}as:T List. ((n \mleq{} ||as||) {}\mRightarrow{} (\mforall{}i:\mBbbN{}n. (firstn(n;as)[i] = as[i])))\mkleeneclose{}
THENM (HypBackchain THEN Auto)
)
Home
Index