Typing mathematical symbols

The Greek characters are obtained in TeXmacs by combining the hyper modifier key H- with a letter. For instance, H-a yields α and H-G yields Γ. Recall that the F5 key is equivalent to H-, so that ρ can also be obtained by typing F5 r. Similarly, F6, F7, F8 and S-F6 can be used in order to type bold, calligraphic, fraktur and blackboard bold characters. For instance, F8 m yields m, S-F6 R yields R and F6 F7 Z yields Z.

Greek characters can also be obtained as “variants” of Latin characters using the tab-key. For instance, p tab yields π. The tab-key is also used for obtaining variants of the Greek letters themselves. For instance, both H-p tab and p tab tab yield ϖ.

Many other mathematical symbols are obtained by “natural” key-combinations. For instance, - > yields →, - - > yields ⟶ and > = yields ⩾. Similarly, | - yields ⊢, | - > yields ↦ and - > < - yields ⇄. Some general rules hold in order to obtain variants of symbols:

tab

is the main key for obtaining variants. For instance, > = yields ⩾, but > = tab yields ≥. Similarly, < tab yields ≺, < tab = yields ≼ and < tab = tab yields ⪯. Also, P tab yields ℘ and e tab yields the constant ⅇ = exp(1). You may “cycle back” using S-tab.

@

is used for putting symbols into circles or boxes. For instance, @ + yields ⊕ and @ x yields ⊗. Similarly, @ tab + yields ⊞.

/

is used for negations. For instance, = / yields ≠ and < = / yields not(⩽). Notice that < = tab tab / yields ≦̸, while < = tab tab / tab yields ≨.

!

is used after arrows in order to force scripts to be placed above or below the arrow. For instance, - - > ^ x yields ⟶^x , but - - > ! ^ x yields ⟶^x.

Several other symbols which cannot be entered naturally in the above way are obtained using the S-F5 prefix. Here follows a short table of such symbols: