... Astronomers have recently discovered about a dozen planets orbiting stars similar to the Sun. ... The Earth is the only known planet which has water in the liquid, solid and gaseous forms. ... A planet is termed "habitable" if it has surface liquid water. The presence of liquid water depends on the planet's distance from its parent star. John Chambers' programme yielded a number of artificial planetary systems, all of which showed at least one habitable, or possibly habitable, planet. ...
... Also note that with fix form text in positions 73 to 80 was considered to be a comment. ... PROGRAM TEST_ADAPTIVE_QUAD IMPLICIT NONE INTERFACE FUNCTION F(X) RESULT ( FUNCTION _VALUE) REAL , INTENT (IN) :: X REAL :: FUNCTION _VALUE END FUNCTION F END INTERFACE INTERFACE RECURSIVE FUNCTION ADAPTIVE_QUAD (F, A, B, TOL, ABS_ ERROR ) RESULT ( RESULT ) REAL , EXTERNAL :: F REAL , INTENT (IN) :: A, B, TOL REAL , INTENT (OUT) :: ABS_ ERROR REAL :: RESULT ...