LET Value Expression

Syntax

letValExpr	“LET” assignment (“;” assignment)* “IN” valExpr “NI”
assignment	varDecl “=” valExpr

Semantics

Introduce variables

Examples

Simultaneously define multiple variables

The statement

LET a = 5; b = 3; c = 8 IN
   ...
   LET a = 1+b; b = 2+a; c = a*b IN ... NI
   ...
NI

defines two times three new variables (a, b, and c).

Inside the first LET IN NI block except the second LET IN NI block, the values of a, b, and c are 5, 3, and 8, respectively.

Inside the second LET IN NI block, the values of a, b, and c are 4, 7, and 15, respectively.