A set is lightface if it is the complement of a set.

Its lightface analog is known as the analytical hierarchy.

He is especially associated with the development of the effective, or lightface, version of descriptive set theory.

In fact, the strategy for a universal lightface analytic game has the same Turing degree as 0.

The lightface Borel hierarchy can be defined on any effective Polish space.

Each lightface Borel set has infinitely many distinct codes.

It includes the study of lightface pointclasses, and is closely related to hyperarithmetical theory.

In particular, it focuses on lightface analogues of hierarchies of classical descriptive set theory.

This produces that hyperarithmetic hierarchy, which is the lightface analog of the Borel hierarchy.

A code for a lightface Borel set gives complete information about how to recover the set from sets of smaller rank.

This is the origin of the Church-Kleene ordinal in the definition of the lightface hierarchy.

Pitchers' statistics for this season are in lightface; the 1986 numbers through 38 games are shown in boldface.

The code for a lightface Borel set A can be used to inductively define a tree whose nodes are labeled by codes.

Cloister Lightface (1924)

Adstyle Lightface (1911)

The lightface Borel hierarchy is an effective version of the boldface Borel hierarchy.

Cloister Lightface Italic (1925)

Note that the bold font in this symbol is not the Wikipedia convention, but rather is used distinctively from its lightface counterpart (see analytical hierarchy).

The lightface Borel hierarchy extends the arithmetical hierarchy to include additional Borel sets.

Barnhart Lightface (1914, BB&S)

Donald A. Martin and Leo Harrington have shown that the existence of 0 is equivalent to the determinacy of lightface analytic games.

The most common usage in transport timetables for air, rail, bus, etc is to use lightface for a.m. times and boldface for p.m. times.

The analytical hierarchy of sets classifies sets by the formulas that can be used to define them; it is the lightface version of the projective hierarchy.

This relationship between lightface sets and their indices is used to extend the lightface Borel hierarchy into the transfinite, via recursive ordinals.

Not until 1884 did the Italian printer Giambattista Bodoni use boldface to describe a darkly thick, or bold, typeface, which looks like this and is easily distinguished from lightface type.

The same results also showed that the light-faced taxa pipile, cumanensis and cujubi are not, as was sometimes suggested, conspecific.

The big, square Korean face, especially if it lacked a pronounced Mongolian fold about the eye, re- sembled the light-faced black.

On the exterior of the building there is a granite base that is four feet high with the rest of the building covered in Indiana limestone and light-faced brick.