Thank you very much! It seems that grid (antik) is automatically loaded with gsll by quicklisp. But that doesn't seem to be the problem: both
(grid:copy-to (vector 0.0d0 1.0d0 (sqrt 2.0d0) 3.0d0))
and
(vector 0.0d0 1.0d0 (sqrt 2.0d0) 3.0d0)
seem to give the same result - which should be the endpoints and singularities for computation of a numerical integral by use of the GSL QUADPACK routine QAGP, implemented in gsll as integration-qagp. But the command
(gsll:integration-QAGp 'integration-test-f454 (grid:copy-to (vector 0.0d0 1.0d0 (sqrt 2.0d0) 3.0d0)) 0.0d0 1.0d-3 1000))
fails with a slew of errors. The debugger's first backtrace is
((:METHOD NO-APPLICABLE-METHOD (T)) #<STANDARD-GENERIC-FUNCTION GRID:FOREIGN-POINTER (1)> #(0.0 1.0 1.4142135623730951 3.0)) [fast-method]
Given that the grid command above works without any errors, I don't understand this at all. But then, as I say, I seem to have programmed in many languages over the years - with the lamentable absence of lisp. So if my questions seem trivial and naive, my apologies!