## 5.238. lt

Origin

Arithmetic.

Constraint

$\mathrm{𝚕𝚝}\left(\mathrm{𝚅𝙰𝚁}\mathtt{1},\mathrm{𝚅𝙰𝚁}\mathtt{2}\right)$

Synonyms

$\mathrm{𝚛𝚎𝚕}$, $\mathrm{𝚡𝚕𝚝𝚢}$.

Arguments
 $\mathrm{𝚅𝙰𝚁}\mathtt{1}$ $\mathrm{𝚍𝚟𝚊𝚛}$ $\mathrm{𝚅𝙰𝚁}\mathtt{2}$ $\mathrm{𝚍𝚟𝚊𝚛}$
Purpose

Enforce the fact that the first variable is strictly less than the second variable.

Example
$\left(1,8\right)$

The $\mathrm{𝚕𝚝}$ constraint holds since 1 is strictly less than 8.

Symmetries
• $\mathrm{𝚅𝙰𝚁}\mathtt{1}$ can be replaced by any value $<\mathrm{𝚅𝙰𝚁}\mathtt{2}$.

• $\mathrm{𝚅𝙰𝚁}\mathtt{2}$ can be replaced by any value $>\mathrm{𝚅𝙰𝚁}\mathtt{1}$.

Systems

lt in Choco, rel in Gecode, xlty in JaCoP, #< in SICStus.