# invoke this program thus: a68g -prec 500 a68x#
MODE R = LONG LONG REAL;
R x := -35;
REAL dx = .1;
R s := 0;
WHILE x < 35 DO s +:= long long exp(- (x*x)); x +:= dx OD;
s *:= dx;
R p = long long pi;
print((p, new line, s*s, new line, s*s-p))

# a68g -prec 500 a68x
+3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067982148086513282306647093844609550582231725359408128481117450284102701938521105559644622948954930381964428810975665933446128475648233786783165271201909145648566923460348610454326648213393607260249141273724587006606315588174881520920962829254091715364367892590360011330530548820466521384146951941511609433057270365759591953092186117381932611793105118548074462379962749567351885752724891227938183011949129833673362e  +0
+3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067982148086513282306647093844609550582231725359408128481117450284102701938521105559644622948954930381964428810975665933446128475648233786783165271201909145648566923460348610454326648213393607260249141273724587006606315588174881520920962829254091715364367892590360011330530548820466521384146951941511609433057270365759591953092186146740635772027283565202487095236272087186145025881288778231418637275286349975037771e  +0
+2.935870316023417844665441263285630933761879314012856388700348045426333722014136440830000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000e-428
#