Commit 2024-02-21 16:46 f17e2324
View on Github →refactor(MeasureTheory): redefine ≤
on measures (#10714)
Redefine ≤
on MeasureTheory.Measure
so that μ ≤ ν ↔ ∀ s, μ s ≤ ν s
by definition
instead of ∀ s, MeasurableSet s → μ s ≤ ν s
.
Reasons
- this way it is defeq to
≤
on outer measures; - if we decide to introduce an order on all
DFunLike
types and migrate measures toFunLike
, then this is unavoidable; - the reasoning for the old definition was
"it's slightly easier to prove
μ ≤ ν
this way"; the counter-argument is "it's slightly harder to applyμ ≤ ν
this way".
Other changes
- golf some proofs broken by this change;
- add
@[gcongr]
tags to someENNReal
lemmas; - fix the name
ENNReal.coe_lt_coe_of_le
->ENNReal.ENNReal.coe_lt_coe_of_lt
; - drop an unneeded
MeasurableSet
assumption inset_lintegral_pdf_le_map