pith. sign in
theorem

one_div_pos_of_pos'

proved
show as:
module
IndisputableMonolith.Compat.Mathlib
domain
Compat
line
15 · github
papers citing
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plain-language theorem explainer

Establishes that the reciprocal of a positive real number is positive. Analysts working with inequalities or divisions in real analysis would cite it to maintain sign consistency. The proof is a one-line wrapper that rewrites division and applies the standard inverse positivity result.

Claim. For $x$ a real number, if $x > 0$ then $1/x > 0$.

background

The Compat.Mathlib module supplies small alias lemmas and helpers that stabilize names across Mathlib versions and cut duplication. This theorem re-expresses the positivity of the reciprocal using the definition of division as multiplication by the multiplicative inverse.

proof idea

One-line wrapper that applies the inverse positivity lemma after simplifying the division notation.

why it matters

Supplies a stable name for a basic positivity fact, preventing version-specific breakage in the Recognition Science mathematical layer. It supports any downstream argument that divides by positive reals without introducing extra hypotheses.

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