Graffiti Graffiti Graffiti (both singular and plural; the singular "graffito" is very rare in English except in archeology) is writing or drawings made on a wall or other surface, usually without permission and within public view. Graffiti ranges from simple written words to elaborate wall paintings, and it has existed since ancient times, with examples dating back to ancient Egypt, ancient Greece, and the Roman Empire. In modern times, paint (particularly spray paint) and marker pens have become the most commonly used graffiti materials. In most countries, marking or painting property without the property owner's permission is considered defacement and vandalism,
Singular measure Singular measure In mathematics, two positive (or signed or complex) measures "μ" and "ν" defined on a measurable space (Ω, Σ) are called singular if there exist two disjoint sets "A" and "B" in Σ whose union is Ω such that "μ" is zero on all measurable subsets of "B" while "ν" is zero on all measurable subsets of "A". This is denoted by formula_1 A refined form of Lebesgue's decomposition theorem decomposes a singular measure into a singular continuous measure and a discrete measure. See below for examples. As a particular case, a measure defined on the Euclidean space