startAtStart
Constrains the delay between the starts of two interval variables.
Syntax
constraint startAtStart(intervalVar a, intervalVar b, intExpr delay = 0)
Parameters
-
a: first interval variables -
b: second interval variables -
delay: exact delay between starts ofaandb. If not specified then zero is used.
Description
The function startAtStart constrains interval variables a and b in the
following way. If both intervals a and b are present then interval b must
start exactly at startOf(a)+delay. If a or b is absent then the
constraint is automatically satisfied.
The default value for delay is zero. Note that delay can be negative.
Example
There is mandatory task x and optional task y. If y is performed then it
must start at the same time as x.
x = intervalVar(length = 5..10);
y = intervalVar(optional);
startAtStart(x, y);